I was also using winxp MCE on an old laptop but xp stopped working after Christmas. The laptop cannot not handle vista media center and barely vista by it self.
This prompted me to finally make the move to Linux.
The problem is that I do not know Linux. I used unix back at the university but only learned ls, cd and a few other commands. Luckily I know other computer stuff and I decided to give it a try.
I can tell you in advance it takes a LOOT of time if you are not an Linux expert. Yes, you can get Ubuntu to run in a hour, but to get to the level of vista mce out of the box takes a lot of work.
The good news is that the sw is great and I prefer it to vista when finally set up correctly.