My understanding is most old towers have 3 T1s which provide 4.5 mbps up/down so not that fast, but the good part is they're completely dedicated to Sprint unlike a consumer cable connection where the bandwidth is shared.
NV sites should have 100 mbps now with the option to more easily upgrade when the need is there. The best part is that the new connections are about the same monthly cost to Sprint so besides the installation labor and one time fees its a free upgrade, thus driving the $ per mpbs down significantly and allowing Sprint to continue offering unlimited data and sell excess capacity wholesale.