"People seem to think that T-Mobile's network is the only one of the four major carriers that will really rival Sprint's post-NV network in terms of technology."
I can only speak for myself, but with WCS and AWS spectrum respectively, both AT&T and Verizon(especially Verizon) can build plenty fast networks. Both companies have the cash to build out NV style projects whenever they feel they need to. They might limit the modernizations to the cities, but I see LTE on AWS for Verizon having a greater footprint than T-Mobile's entire network. Also, everyone but T-Mobile has <1GHZ spectrum, so really T-Mobile is in a really tough position coverage wise. Price and siding with the evil empires are a bigger issue for me than network potential. Oh and AT&T's current network is crap around here.