For the most part I'm happy, it was a little weird to deal with tiles on a desktop, and installing programs, having them disappear into the void if there was no tile created.
Seems stable. Some drivers for older devices are dropped off. My mouse works but the extra buttons are not; yet.
Be careful about going from XP 32 to Win 8 64. I was on the chat with support for hours, he never did fix the issue, it seemed to fix itself. Make sure you do NOT install Win 32 bit first. Bad bad idea.
I have to warn you though, wrestling control of this OS from Microsoft is akin to taking on a pit bull, it does not want you to have much control and that has caused a few issues for me. Run as administrator is the catch all that doesn't do-all.
For those using FSX, no issues.