I have done this to help with battery life, but cannot claim to have had more than total of maybe 5-10% gain? Considering I disabled background data for everything but Yahoo Email, Messaging, Android OS, and System Critical programs (literally everything else... if it was on the Data Usage screen and it wasn't one of those, it got it's background data disabled), I would have expected bigger gains. After all, is it not the case that my phone no longer needs to sync constantly?
However, I AM on WiFi about 90-95% of the time, so it is hard to really compare. I could turn off WiFi, but the whole reason I use it is because it greatly improves battery life, and unless I happen to be in one of the few parts of my house/work/school where WiFi is spotty (i.e. Not near router or AP), the speed difference between LTE and 20/40mhz WiFi is not noticeable outside of speed tests.
I just ran two speed tests right now, and the results will follow... (11:18PM, Inssider shows 14 current detectable networks on both devices, so I have 2.4ghz set at Channel 1+4, with only 3 other networks on the channels and both with signals lower than -130dBm, and 5ghz set at 36+40 and currently no other routers detectable on the 5ghz spectrum).
WIFI THROUGH-PUT SPEED TEST
(NEW Asus RT-N66U N900 Dual-Band Wireless Router with 3x +7dBi gain omnidirectional/dual-band antenna located exactly 11 feet away, zero interference, line of sight)
*These tests are for throughput, so to eliminate my 50Mbps Down/20Mbps Up Cable connection as a variable, it is being tested with my Home Network's 4-Drive RAID10 Network Storage (4x3TB Seagate Barracuda 7200RPM 64MB Cache SATA3 newest-gen drives; 6TB space total) connected via USB3.0 directly to the router, with average LAN transfer speeds over 25' of CAT7E Wire being >500Mbps Sequential Read and >200Mbps Sequential Write (these HDDs are FAAAAST)
**The test is exchanging the exact same 910MB HD Video Clip
***I will include a set to show average internet access speeds at 11' and line-of-sight with this phone
2.4ghz (20mHz width)
Test 1: 22.4Mbps Down // 4.3Mbps Up
Test 2: 23.1Mbps Down // 5.8Mbps Up
2.4ghz (40mHz width)
Test 1: 26.9Mbps Down // 7.2Mbps Up
Test 2: 26.7Mbps Down // 8.5Mbps Up
5ghz (20mHz width)
Test 1: 33.8Mbps Down // 10.2Mbps Up
Test 2: 32.3Mbps Down // 9.5Mbps Up
5ghz (40mHz width)
Test 1: 38.5Mbps Down // 14.8Mbps Up
Test 2: 41.2Mbps Down // 17.6Mbps Up
Dual-Band Test (Full Capability)
Test 1: 51.8Mbps Down // 19.2Mbps Up
Test 2: 50.4Mbps Down // 21.1Mbps Up
Pretty quick, but compared to the triple-antenna dual-band 450+450 network card in my laptop, the speeds are only about 1/2-1/4th at the same distance (attributable to the much more powerful antenna in the laptop).
WIFI INTERNET SPEED TEST
(exact same setup as above, only variable being Time Warner "Road Runner Ultimate" Cable Internet with Motorola Surfboard DOCSIS3.0 Modem connected via Quad-EMI-Shielded COAX in-wall into 5' RG-6 4-Layer Coax Cable, then 1meter CAT7E Cable to NT-R66 Router; Cable Internet advertised speed is 50Mbps DOWN and 20Mbps UP consistent with "Speed Boost" up to 80Mbps DOWN and 40Mbps UP with DOCSIS3 modem)
Dual-Band Test (Maximum Bandwidth)
Test 1: 21.8Mbps Down // 12.3Mbps Up
Test 2: 38.9Mbps Down // 21.7Mbps Up
*Test 3: 26.4Mbps Down // 14.2Mbps Up
*Test 4: 25.9Mbps Down // 13.8Mbps Up
*Tests 3-4 were conducted due to the abnormally high speed of Test 2, which I cannot explain unless everyone else in the neighborhood suddenly logged off... However, these speeds are pretty good considering it is wireless and WPA2/TKIP2 Encrypted.
LTE aka "4G" SPEED TEST
(all background data disabled, "full bars" equating to -87dBm signal strength; I have seen this as strong as -40dBm, so these numbers should reflect and average of my speeds, over all times and places where 4G is present)
*Tests will be conducted by down-/up-loading a (same every time) 100MB File from my own personal "Cloud" server
Test 1: 23.72Mbps Down // 17.23Mbps Up
Test 2: 28.11Mbps Down // 18.17Mbps Up
Test 3: 14.83Mbps Down // 12.97Mbps Up
Test 4: 19.98Mbps Down // 21.03Mbps Up
That is the ONLY time I have seen my phone UPLOAD faster than DOWNLOAD! Maybe a network issue, as I did just run a 100MB HD Video file across the same towers 8 times in a very short time period, or maybe someone else was doing the same things, I have no idea.
Regardless, if you have good WiFi, DISABLE BACKGROUND DATA because it will AUTOMATICALLY COME BACK ON WHEN YOU TURN OFF WIFI!!