Some good info on why none of the networks currently marketed as 4G, are anywhere close to 4G performance can be found
HERE.
"Verizon claims that tests indicate it is getting download speeds of between 6Mbps and 12Mbps on its precommercial LTE network." The other networks "4G" top end barely makes it to Verizon's lower end of performance. Considering the average 3G was 1.5 Mbps, you're looking at a 4x improvement at a minimum over current 3G networks.
So, if you never knew what is was supposed to deliver (peak downloads of
100Mbps), Verizon has the best performance option, but currently the most limited
coverage, excluding ATT which, as usual, isn't even in the game.