I am using i337 with tmobiles sim card. I get 4g at over 10mbs and even over 20mbs on some good dsys. I usually use att roms although I've found that i9505 and tmobile work too. Just have to stick with loki'ed kernels. Hope this helps.
Note 10.1 tethered to an AT&T S4 powered by a T-mobile's sim card.