I don't have 4G in my area yet so have had it set to CDMA only since day one (got it on launch day)....I use WiFi when I'm at home, otherwise on 3G with pretty much no restriction to data connection (i.e. on all the time) and I really feel like I've been using it quite a bit - not sure I'd consider it "heavy", not been doing a lot of music or video streaming, but first Android phone so have been spending a lot of time with the phone/display on getting familiar with the OS, messing with settings, trying out different looks, downloading various apps (most of what I've used the data connection for at this point) and getting addicted to that stupid X Construction game! LOL But since Thursday, I've managed to get about 15-16 hours of use per day......some of those days I've plugged it in to a USB port for brief periods, so it's gotten a little extra charge....but not a ton. Got it at Costco so got all the dock (which I really haven't used) but I figure I have plenty of options to juice the phone up when necessary as my usage patterns change......and we'll hopefully be getting 4G by years end...