I’ve had my S3 for a month or so. I’m really liking the camera, zero shutter lag and it’ll take a burst of up to 20 shots. Perfect for when you just know someone’s going to do something stupid, but aren’t sure exactly when it’ll happen. It’s pretty quick, I don’t have any lag or hesitation. The battery will last 12-14 hours with light texting, social networking and web browsing, and 9 hours of that is in a low signal environment because I work in a metal building with no access to wifi. It seems to be built pretty solid as far as modern smartphones go.
The only downside I’ve found so far is that the home key turns the screen on after it times out, and I’ve found the key getting pressed in a pants pocket or backpack, and all kinds of weirdness can ensue if stuff is touching the screen in random places while it’s bouncing around. Apps get opened, settings can get changed, and the dreaded butt call can be made. I don’t use any kind of security lock on the phone, so if you use the pattern or passcode unlock feature, it would likely prevent such hijinks. You might also be able to change the home key wake up in settings somehow, but it hasn’t bothered me enough to investigate.
The Google Now feature that comes in the new Jelly Bean builds is pretty awesome, but just a tad creepy once in a while. It reads your Gmail and gives you flight information reminders and shipment tracking info for stuff you order online. Like a really helpful stalker.