After installing MCE and getting it all working I decided to install Beryl for the laugh, fully expecting it to break MCE completely.
I found that other than a couple of minor quirks the 2 complimented each other quite nicely.
Sabayon would therefore seem like the perfect OS with MCE to me. They're both OpenGL front ends and they're both damn good products. An openGL driven desktop combined with openGL MCE could quite easily create something rather special I would have thought. Or am I just dreaming?