I have the unlocked version (UK) that I purchased from Amazon and LOVE IT!!
Advantages:
iPhone like home key (huge difference to me)
No Bloatware, NONE
Native Tethering Ability active out of the box(I have an unlimited plan and I use it quite often and have not received any notifications from AT&T, but I'm sure that I'm not getting anywhere near 5GB a month)
Contract open to use on something else when I feel like it.
I'm telling you, I've had every phone out there and this one is the bomb, hands down. The only problem that I've had with it has been the keyboard problem that Swiftkey had with the native email app on Samsung, but that just got resolved a few days ago and it finally works like it used to. I find that there's a lag in getting the screen to come on once you hit the home button that's kind of annoying, but that's the best I can come up with as far as a problem on this phone.
When I took the phone into AT&T to get it activated, the crew were all over it and kept saying that they wished they had this phone over the model that they have because of the home key being on the front rather than the side.
Hope that helps....