I'm seeing the "heat issue" discussed in forums all around. Apparently the OTA does not touch it quite enough, causing some users to just throw their hands in the air and go for another device (many the D3).
This makes me wonder if the official OTA will address it directly.
As for me, my two week old X2 most certainly does get good and warm as I use it.. just on the threshold of "hot," or "uncomfortable." But still not a deal breaker for me (I got rid of my D3 because I found myself never using the slide out, good as it was just no need for it coming off a Fascinate).
I have zero of the other mentioned issues about the X2: no reboots at all, no screen freezes, no lag at all (very fast and snaps from one screen or app to another without delay).
I found the leaked 2.3.4, but did not install it, wondering if the official might address the heat indirectly with better CPU functionality, etc.