Tmobile vs ATT (Galaxy vs iPhone)?

I'm still up in the air about the newest Galaxy and iPhone. I hear iPhone 5 is slimmer, slightly longer screen, and faster with the LTE. Those are the main features I continuously hear about. I know there are other things, but I hear a lot of people saying they're disappointed. That aside from those 3 points it's just minimal improvements. I heard the latest Galaxy already has all these features and that iPhone 5 was barely catching up, Galaxy still has a longer screen, and has more features. I'm leaning towards the Galaxy, but I'm still up in the air about it. What is your take on the two phones? Now, currently I live in the San Antonio, TX area. I see ATT stores everyone in San Antonio, but I never see any Tmobile locations which leads me to believe ATT download speeds would be faster. My dilemna ist hat ATT doesn't offer an unlimited data while Tmobile does. So, does anyone know if Tmobile data speed is comparable to ATT in this area? I'm feeling ATT would be faster, but I don't know for sure, and if so...how much faster? If it's only a small amount I don't care...I'd rather have unlimited data. The type of speed I'd want is at least good enough so I can watch a movie on Netflix and not have it pausing repeatedly for buffering throughout the movie.