i have owned the HTC One X (ATT) for 3 days, and i am blown away by the S4 speed. Coming from the HTC Evo Shift 4G on sprint, it is a world of difference and improvement. The radios are amazing with reception thus far (not sure if that is ATT v sprint or the phone, but I'm sure the phone is helping as well) getting service 3x what i used to get with other phones. The battery seems to die a bit faster, but from what I've read that should improve with use. It has a tyipcal HTC Sense UI, but moves lighting fast with amazing display quality. I am typically an Apple guy, but the design and specs on the One X steered me away from the iPhone and I couldnt be happier!