I traded in my HOX for S3 and regret it!
The phone feels like a toy in your hands compared to the one x. Don't get me wrong the S3 is a decent phone but I really feel the one x is superior. The killer for me is the display on the S3 is pretty bad. It's not nearly as bright as the one x and the clarity of small letters is MUCH better on the one x. The auto brightness features is horrid. It's always to dark. The smart stay feature (the one that keeps the screen on when you are looking at it) only works maybe 25% of the time. The tap the top of the phone to scroll back to the top of the page rarely works for me. I do like how you can play videos in a small window and do other things like surf the web at the same time. It's pretty cool.
If any of you are thinking of making the switch and have any questions feel free to ask and I'll do what I can to answer.