BTW, I don't blame you for sticking with Sprint, despite steveu694's assertion that to do so means you'll be without data until next year. I have a grandfathered SERO plan, myself. And although the Baltimore region didn't get 4G LTE coverage in July (that having been the initial target), it will be turned on here in another 3 weeks. I can't honestly say that it bothers me to be limited to 3G speeds, but I guess it'll be nice to have 4G.
So far, I think Sprint 4G is up and running in Atlanta, San Antonio, Houston, Dallas/Fort Worth, and Kansas City.
Then, like I say, Baltimore comes online in another few weeks.
And next month Boston, Washington DC, Chicago, Los Angeles, and I think one or two other cities, are scheduled to be activated.
I forget the rest of the roll-out cities/dates, other than NYC/Westchester/Northern NJ/Central NJ, in November. I recall that one, because my brother-in-law, in Central NJ, is on Sprint, and has an S3, and was jokingly whining about how unfair it is that I'll have 4G LTE so much sooner than he will.
Anyway, I don't know where you're located, but it sounds like within the next 90 days (give or take a little), a non-trivial percentage of the public will have access to Sprint's 4G LTE network, with the target of 120+ million people covered by the end of the year (ie. less than another 6 months). Although it's true that it'll be a year more than that before the goal of 250 million people is met, and probably nearly that long before HD Voice and 800MHz network upgrades start to really kick in. (Bear in mind, when I say "x million people covered," I mean, of course, that that's how many people live in the 4G LTE areas in question - not that that's how many people will actually be Sprint subscribers using 4G LTE. This, out of a US population of around 310 million.)