I'm on Tmobile. I got mine through my upgrade I had been saving which is why I picked it up in store this morning.
I haven't had much of a chance to test a whole lot on it since I only had it for a couple hours before work. I'll mess around with it more tonight and in the morning and try to post a good review of it tomorrow before I leave for work.
Here is something that I found though. If you use 3rd party music apps like Slacker radio, which is 99% of my music, the music controls now work and automatically appear on the lockscreen while listening to music. Very convenient.