I am no 4G technical guru here, but technically speaking if you do a little researech no carrier really has true 4G.. True 4G is a tech that has yet to be prefected.. Now Sprint and Verizon do have 4G speeds, but if I am correct LTE/Wimax are both still not TRUE 4G?
Still T-mobile and ATT&T using the HSPA network and calling it 4G is something to laugh at...
+1 to Verizon/Sprint
UPDATE:
Here is an interesting link for this thread.. Most people that want 4G have no idea what it is..
4G Shocker! Study finds consumers want what they fail to understand -- Engadget