Just to provide some feedback, I purchased one of the X8s for my father to use. He uses iTunes, so I didn't get to try it with MC, but it ran well enough to encourage me to pre-order the X9. (The X8's display is a tad bit small... but otherwise it was excellent).
My plan is to ONLY run MC on it and only use it for audio, I think that it will be up to the task w/o any problems.
We'll see.