Voice coverage is good, 3G data speeds are all over the place, I see anywhere from 100 kbps to 1 Mbps, mostly in the 100-300 range, higher only late at night and away from the U of I campus. On campus during the school year you are lucky to get 100 kbps much of the time. And this is improved from a year or two ago; Sprint has added some data capacity at most towers but it is still far short of sufficient. There is no 4G yet (Wimax never made it here).