I love my black/black silicrylic. Makes the buttons easier to press, protects the phone and has a really nice feel to it. Plus the bulk it adds isn't really that much when compared to the commuter. The one drawback is that the silicone bit could be a little tighter, but it isnt that noticeable.
ok.. so here's my little input on this. I bought the Incipio Silycrilic thinking I would NEVER need that much protection. I spent this past weekend installing long-tube headers on my 01 firebird formula. In case you aren't familiar with these cars clearances are stupid tight. Most of the spaces my phone was the only real light I could get where I needed it (kudos to TESLA LED!!!). Let me tell you this.. I had my car jacked up 2 ft off the ground, and my phone fell several times from the top of the fenderwell bouncing around on sharp metal objects in the engine bay and finally falling.. yup screen first onto the concrete below. The screen cover that comes with the silycrylic has a few scuffs but nothing major and nothing that made it through to the real screen below. Let me also add the case was covered in as much grease as my hands since I was handling it the entire time. Took the case off the phone washed it with dawn and water, and it's as good as new. ... Five stars from me and highly recommended I'm also gonna duplicate this for a full thread by itself lol.
The otterbox commuter does provide more protection, it is a bit thicker on the silicone side and the hard plastic is harder. The silicone is also a bit of a tighter fit. The Incipio is by no means like a feather or barely there protection, it is substantial enough.
However the Otter box is more slippery to hold and the outside of the Incipio grips better not just in your hand but while laying on a surface.
Also the top power button can be a nuisance to press with the otterbox commuter. Sometimes you have to press it just right or more than once for it to engage. The incipio engages it everytime. Sometimes I wish the incipio felt as protective as the otterbox but i have dropped the phone a few times with the incipio on and it has done its job.
Once in awhile I put on the Commuter, but the Incipio is on my phone 90% of the time.