The bad thing with Sprint is you can not use your phone as a modem unless you buy the wireless broadband 3g or 4g package...and as said above, 3g is capped at 5gb/month and 4g is not in the very few areas it's actually available.
Phone-as-modem is pretty much the only thing I'm concerned about. Alltel offered/offers it without caps, but it looks like I'm losing this option which means I lose internet entirely since no DSL/cable/wifi/satellite/etc in my area.