I generally keep it on 3G to conserve the battery and when I get into my massive office building each day the signals at 1 bar or 1x at my desk with .2mb download speeds. But I noticed the last few days when I have it on 4G and go into the building, it stays at 4G and I'm getting 8-10mb downloads. But if I'm on 3G and turn on 4G in the building, it stays at 1 bar 3G. That was a great discovery, works great now as long as I keep it plugged in.