I was able to get an HTC One X (LTE) from AT&T last night.
If you have questions about the AT&T version post here and I'll try to answer.
First few observations:
Lightning fast, there is no hesitation doing any action. It's a bit surreal coming from a Captivate.
Camera is awesome.
Thin, light, but solid build, looks good and doesn't feel cheap.
You can't turn off LTE. If you go into Settings -> Mobile Network, there is no option for "Preffered Network Mode" like on the Galaxy Nexus or Rogers HTC One X. Really hoping to get this fixed via OTA or custom ROM as there is no LTE anywhere near me.
Stock browser doesn't have a dedicated "tabs" button. You have to press menu to get to your tabs. Kind of annoying, not sure if that is just an HTC thing or if this is the first phone like that. I'm just going to start using Chrome since it has a tabs button.
Sense 4.0 is nice, it's not obtrusive and actually improves on the stock ICS experience instead of replacing it altogether. I love the WebOS style recent apps list. It really looks nice.
I read some people saying they were seeing some yellow wash out on some screens, and I think mine is OK, but certain apps, particularly games do have a yellow tint to them, but stuff like the homescreen and google maps look great. Temple Run has a pretty clear yellow tint to it when compared with a Galaxy Nexus running Temple Run. Not sure what to make of this. Maybe something else that can be fixed in an OTA.
Here's the detailed software info:
HTC Sense Version
HTC SDK API level:
HTC Extension version:
SMP PREEMPT Sat Apr 7 01:37:15 CST 2012
1.73.502.1 CL54373 release-keys