i've had my S4 for 5 days now. all I can say is wow. coming from the Rezound, this phone is worlds apart. my biggest fear was the overheating that some people are/were having, and I have yet to feel this phone get past warm, even after 20 minutes of video streaming. the slight lag is there, but it doesn't bother me in the least. battery life has been phenomenal. my first full day with the phone, I turned off GPS and bluetooth, took it off the charger at 6:30 am. at 11:30pm, I still had 45% battery, and you know I was fiddling with the phone all day long. video streaming, Candy crushing, downloading apps from the market, etc. I did load up Google now, but noticed a serious pull on my battery life, so I disabled that ASAP. so far, the phone is everything I expected, and with my Spigen slim armor case, is well protected.