I had st att sim and IMHO there not worth anybody time! In their TOS they say you can only use the data for checking email and little web browsing, then they say everything else is to be used of wifi!
On howardforums people say keep it under 100mb daily and under 2gb a month. But now they throttle you if you use over 100mb a day! Then it took me almost a week to get my data speeds back to normal! Had to get on their facebook and complain over and over until they finally said they found the issue! THEY WILL NOT TELL YOU A DATA LIMIT, THEY WILL NOT ADMIT THAT THEY ARE THROTTLING! You do get postpaid coverage on the att sim, which is great with the roaming but after dealing with the issues and the run around and the fact its 50+ after tax for me in my state i don't see the advantage besides being able to use anything other than a android.
Metropcs has 4glte, not as fast as verizon but for what you pay for they are acceptable. Their coverage is NOT! Only reason why i on the fence for considering them. cause in my area small towns dont have coverage BUT all the metro areas in Texas has 4g lte covered!!! which is a nice plus! I guess its back to the drawing board....
Also VM the highest you will see is 3.1mbps same goes for verizon on 3g data side! 4g can get higher but metropcs having the 4glte for all slogan now if you live in a good/great metro area your speeds should be around 3-7mbps.