I have the Inc2 and the DX. I honestly like them both. My X is not rooted, but I absolutely can't stand Motoblur, so I use Go Launcher. Sense on the Inc2 is nice just as is, but I have also tried Go Launcher on the Inc2, and it works just fine.
The Inc2 is a nice improvement from the Inc (which I had for a short time) in a very important (to me) way. The call quality is outstanding - nice and loud and perfectly clear. Signal strength seems better and more stable (although you can't judge from the signal bars) than the original Inc too. Of course I've never had a complaint about the call quality or signal strength on the X - both are great.
I like the size and shape of the Inc2 - it's not as clunky and rectangular as the X. It's also a nicer shape than the original Inc - more rounded and smooth.
The X wins hand down in one area that's important to me -- the font size in the native menus and apps on the Inc2 are tiny - way smaller than on the X. I realize that's due in part to the screen size difference, however, the font size in the contacts app, for example, is even smaller than the font size on my Droid Pro, which has a really tiny screen.
If you prefer physical buttons, then you will miss those on the Inc2. I happen to like the virtual menu buttons on the Inc 2 a lot better than the clicky keys on the X.
Battery life is a tad better on the X, although again, battery life on the Inc2 is way better than it was on the original Inc. I have the extended battery, so battery life is never an issue. Even on the stock battery I was getting through the day - I just like that extra insurance.
All in all, the Inc 2 is nice phone. Is it dramatically better than the X? Probably not, unless you really are dying for a front facing camera, or you prefer HTC phones in general. I have not used the ffc yet... so I'm not sure how important it will turn out to be.
Love both phones, but will probably sell the Inc2 while I can still get decent money for it. Or maybe I'll keep it.......... I do really like it!