im on tmobile, They say their unlimited, but drop you down to 3G after you hit 30GB of transfer, and they dont count Netflix/Hulu or youtube traffic against thier use. I average about 20 gigs
Ive also dumped comcast and use the hotspot, i get 10GB there, then it drops down to 512k unlimited. Sounds slow, but the kids just use it for web browsing, and surprisingly, you can still stream Netflix and Youtube without buffering. Only thing that sucks is that it doesn't work when my phone inst in the house...