That's not exactly true either. Some 3G upgrades have come online before 4G LTE. Alcatel Lucent is notorious for working on 3G upgrades prior to completing 4G LTE in their markets. NYC being the prime example of that. The network is being rebuilt from the ground up. It obviously takes time. This clearly isn't one of those band-aid operations that other providers like to do.
well.. i am here to say...
i live in Dallas/ft worth Texas..one of the first to get 4G LTE sprint.
my 3G sucks.. and has sucked for close to 2 yrs. below 500kbs .. often below 100kbs