Chamonix does take a little more work than Morzine. It’s harder to find the good stuff, which is more spread out (most days begin with a half hour train ride). It takes a little planning, I found. If you just want to show up and ride, go to Morzine. Also, Morzine has more lift infrastructure. You’ll spend more time climbing/pushing in Chamonix.
Ha, ignore all that bollocks, it’s awesome. I’m really just trying to talk you out of it because there are only a few singletracks there, but really, really, really sweet ones. Only they’re very fragile – I do not want to see them go the way of BKB in Peaslake, which they surely will if CHX becomes the “go to” destination in place of Morzine.
Munque-chick: yes, mainly. I don’t actually know where the holy grail trail is, which tends to be the one everyone wants to do…