Every time the Bionic or Nexus is mentioned, it seems we only have a bunch of fanboys for each phone. I really wanted to get an honest comparison of the two phones- not by some tech site that gives no specs on the CPU besides clock speed and considers more megapixels an improvement in phone cameras. So let me give my background.
I've been the proud owner of the Bionic since its release last fall. I jumped ship on one of the leaked updates (was it 5.7.893?) and got stuck there for a while. I spent countless hours trying different gingerbread and ICS roms. Coming from an OG droid, it was a little tedious because of the locked bootloader, but between Theory Rom, Eclipse, Liberty, and all the beta ICS roms, I can say I honestly enjoyed it. The phone makes every 3D game I tried look beautiful- coming from a PC gamer, too. But, the lack of ICS, proper hardware acceleration, and kernels was really bugging me. After my brother got a Galaxy Nexus, I decided I would get one too with a family member's upgrade (who still insists on using a flip phone) since this would be my last one with unilimited data. I've had a chance to test out all my usual apps, 2 or 3 roms, kernels, etc, so I've got a good taste of both phones.
It might seem silly that we complain when manufacturers skin a phone, buy a Nexus device, then install a rom with some heavily modded theme, but at least you have the choice that way. This was my biggest grip with the Bionic. Blur does have a very consistent look throughout, but I've been a high framerate enthusiast because of my PC gaming background, so Blur really bothered me. Some roms deal with this well without being too invasive, so there are definitely options for Bionic users. On the Nexus, stock ICS looks and feels beautiful. There have always been a few little rough edges in Android and in custom roms, but these seem to be almost completely ironed out in the Nexus. I feel comfortable letting iPhone users compare my Nexus' UI to theirs, which is something I couldn't completely say with any rom on the Bionic. Since they both can run custom roms (albeit with much more difficulty on the Bionic), you can get around some of these issues.
This is were Bionic users will be happy. Both phones use the SGX 540. However, the Bionic is using a 480 screen where the Nexus is running a 720 screen. Crunch the numbers, and the Bionic has around 500k pixels, the Nexus around 900k pixels. Less pixels equals much better framerates in 3D applications, assuming everything else is equal. This was noticeable in games like Modern Combat 3, ShadowGun, and Wind-up Knight.. They're still playable, running at 30+ FPS or more as I can see. Considering movie theaters only give us 24 FPS, this isn't a huge problem for most people, but still a big victory for the Bionic. Why almost every Android manufacturers picks a GPU worse than the latest iPhone, I don't know, but they do. But, how much do you really play 3D games? I use 2D applications MUCH more often- and this is where the Nexus shines out. Since ICS has hardware acceleration, and every game I tried utilized it without being forced (which broke other important apps for me like Ultimate Guitar Tabs), games like Angry Birds, The Impossible Game, Glow Hockey, Abduction, World of Goo, and Cut the Rope run at a perfect 60 FPS even on stock system software. Emulators seem to work equally well. MarioKart in N64oid runs at full speed, so I'm happy. Temple Run also keeps up at a full 60 FPS (diving a bit if you get a system popup like adjusting volume, but this is expected). The near-system-wide GPU acceleration on the Nexus is really nice. Web browsing (though they cheated at rasterized the web page like the iPhone), Facebook, Settings, Launcher, everything is butter smooth. For all practical purposes, it exceeds expectations, and still keeps up decently with 3D tasks.
The Bionic has an 8 megapixel rear, compared to the 5 megapixel on the Nexus. The Nexus takes better pictures, and there is seriously no shutter lag. Give it time to focus, of course, but you can manually focus then snap away. They both do 1080p video, but the Nexus can take snapshots during the video (which matters because.... I'm sure it's important to somebody out there...). The front facing cameras are both similar enough I'm not bothered to pull up the specs. They both let you Skype. They both let annoying girls who borrow your phone take facebook profile pics and check their hair in your $700 electronic mirror. And you know they can't tell the difference between 1 and 1.3 megapixels. If your Bionic's camera speed is bothering you, get the app Fastburst Camera Lite, which takes pictures literally as fast as you tap the button at the expense of less resolution (or something like that). The Nexus wins, but the Bionic still does well enough I could overlook it.
The bionic has 4 GB for apps, 4 GB for System/webtop, and 8 GB for data, plus a 16 gig sd card I believe? The Nexus has 32 gigs, and it's split however you need it to be. The Bionic has an SD card slot, but my Nexus has 21 gigs available once set up. How much do you reasonably need? Both have ample space for whatever you want. On a plus note, the Nexus has a single /sdcard folder in the file system. SOOOOO many apps gave me trouble about a separate /sdcard and /sd-ext. This problem is nonexistant in the Nexus. It uses an odd way of mounting that doesn't work with my SyncToy tool in Windows, but everything else is just like a native mount. There is a Nexus toolkit for complete backups, plus cloud/FTP over wifi options for backup, so again, I've got many options. I don't notice any real world lag, so I'll call it a toss up.
Meh. I'm a guy with man-size pockets, so they both fit fine. The Bionic is a little bulkier. It's a little heavier. But it's easier to hold onto. I've found the Nexus almost slipping out of my hand because it's a little slick, and the Bionic has a somewhat rubbery back to grip easier. The Nexus is curvy, which is sorta ergonomic I guess. It feels very nice and lightweight with no case. I really like the Nexus here, but the Bionic feels like I could take it camping naked with no worries. Both are similar in size, so don't worry too much here.
I've seen Nexus drop tests showing little nicks on the back and corners, but screen shattering when dropped face down. The Bionic has an annoying lip that might protect it, so who knows. Get an otterbox if you need protection over form factor. I never used a screen protector on the Bionic, and there's not a single scratch on the screen. The corner lip is very slightly dented when it feel off my leg onto hard cement in a theater, so I would say it deals with minor falls well. Wood and carpet will be much easier than carpet, and I've had numerous similar drops onto these surfaces with no signs of damage. I've been babying the Nexus with a screen protector, since it has some tempered glass besides Corning Gorilla Glass (obviously a fan here). Some people say they go naked with no scratches, but I've seen just as many claim they've got some. If you need a screen protector, don't get the Verizon anti-glare if there's anything else available. It turns the glares into a poop smear and covers anything on the screen with tiny rainbow dots. I was going camping around some sand, which is known to scratch all glass, so I took no chances. So, I guess the Bionic is a little sturdier, but I have good faith in the Nexus assuming it's taken care of.
4.3" on the Bionic, vs. 4.65" on the Nexus. The on-screen buttons use a little bit unless you're watching a video, so it's a little smaller and slightly more standard aspect-ratio-wise. I thought I would be very opinionated about on screen buttons, but I'm pretty indifferent. They work just like capacitive counterparts. One nice thing is that their brightness obviously follows the screen, which is a nice touch in the dark. The Bionic does better outside, and consumes less power being a pentile matrix. It's really bright with beautiful color balance and whites, even on low power settings. However, the scan lines are horrible. After 6+ months with the Bionic, my eyes were all but completely accustomed to it. It was like the guy on the matrix explaining how he doesn't see green characters, but actual people and buildings. The diagonal lines just went away- until I looked at my brother's Nexus and came back. The Nexus' super AMOLED produces nice colors. It gets a little blue if you go down to super-low root only access levels like 1-2. For reference, 20 is standard lowest brightness even in custom roms. I left it on 1 in a theater, went outside, and couldn't see anything until I went in my car. Other than that, the screen is beautiful. And I mean really nice. The colors are so crisp after looking at horizontal lines. However, it does use more battery than the Bionic's, so take your pick. The size is fine either way. I don't appreciate the higher DPI of the Nexus except in very close situations. My eyes are a little near sighted (+2.25 and +1.25 contacts), but I'm typing this on a 1920X1080 monitor with no lenses in complete comfort, so I would guess I'm about average. The notification LED is very large and visible on the Nexus, unlike the Bionic. The blink rate is easily changeable, which is almost impossible on the Bionic (locked to about every 4 seconds).
The Bionic has a simple mini HDMI, which just works (after you install the webtop mod and aren't running an ICS build, or just stay stock, lol). The Nexus has an MHL port. The idea is that you charge it at the same time, which we need in the mobile world, especially when outputting video for long periods. Unfortunately, the standard hasn't been adopted yet, so you have to buy a 30 dollar adapter plus a 3 dollar mini HDMI cable. In the future, we can hopefully just run a cable straight from the tv, which will charge the phone and transfer video. It has support for crazy surround sound (for all the surround sound audio sources you have on your mono phone...) and no latency, according to the makers. It's a little cumbersome. The Bionic has the added plus of the webtop. It's a bit of a novelty. If you have money for a smartphone and HDTV, don't you have a computer? It's fun to play with, and the lapdock could make this a viable alternative to a laptop for some people. There are some real neat mods like a mostly full Ubuntu add-on, which I regrettably haven't had time to tinker with yet.
Out of the Box, neither is terrible. The lack of custom kernels is holding back the Bionic in my opinion. I never had problems geting through any normal day on the Bionic. Playing with it for hours at home might drain it, but there are chargers everywhere in that instance. Using it out and about, I never ran into a problem. The stock Nexus seems a bit better. With a custom rom and kernel, plus tweaking things like automatic brightness and facebook sync, I've gotten though a whole day with 40% left on the Nexus. The Nexus beats the Bionic by a margin, but it really comes down to how you use the device.
I live in a 4G city, so I've never had problems with 4G. I've taken both devices camping, and never dropped a (painfully weak) 3G signal with either device. The 4G signal in town seems the same, comparing both devices with their current radios. I read about everyone's signal strength horror stories, but never ran into any issues myself. The devices perform close enough here I couldn't call it either way. I'm pulling 12 MB/s down, 8 MB/s up right now with the Nexus, which is equal to, maybe a little above what I saw on the Bionic in the same spot. Regardless, data speeds are SO dependent on signal strength, it's really hard to compare unless you hold the devices side by side everywhere. Youtube buffers a whole minute in a few seconds, so what more could you possibly want? This is better than my home internet.
Nexus has it. Bionic doesn't. Do you have a credit card and the ability to text links to friends? Great! Your Bionic does everything NFC does right now, with a little less pizzazz.
They're both big phones, with dual core CPUs, and 4G LTE. They both present weather, casual games, emails, forums, and social networks like a beast. Isn't that 90% of what we all do on smartphones? ICS has some nice GPU acceleration, which I love. The SGX 540 fares better with a lower resolution screen on the Bionic for 3D games- which I also love. But technology has progressed to the point where both devices are still relatively really good at every point where they seem to fall short. From a guy who's had each device for some time and gotten to know and use each one, I can honestly say these are both pretty good phones. Do you want crazy framerates in 2D or 3D content? Given the nature of the web and most apps, I opt for 2D on my phone. Do you really care about loading custom kernels? Many here would, but you've got custom roms either way. Please, Galaxy Nexus owners, stop trolling the comments on every Bionic related announcement. We both have good phones. I would recommend the Nexus, especially to techy people, but don't be disappointed by any means if you're locked into a Bionic on contract for another 18 months. Both phones can run essentially any app in the market, and we'll definitely all agree they can do more than any iPhone ever dreamed of.