I lived in Chamonix for two years.There are masses of trails of every level of difficulty.All the summer lifts give full bike access apart from the Aguile du Midi and the Montenver train.What the Mayor says, and what is overlooked, are very different.
There is no comparison between Chamonix and Les Gets/PDS in terms of technicality.Chamonix is highly technical,Darren Berreclaw holidays there.Its steep,rooty and rocky and offers very little for your average cross country rider apart from the balcons nord and sud.Get a map and check it out..
Les Gets/PDS has a lot of fast flowy marked trails and a brilliant lift system.The official dh tracks and the trails get covered in braking bumps very early in the season,the Swiss less so.There's a lot of un-official building goes on in spring around Morzine which become common knowledge as they get discovered.
Chamonix is a great place to base yourself if you want to mix it up.Pila,Verbier,la Clusaz,Morzine…all just an hour away.Much more well rounded in the evening…
Depends on what you like to ride,but like I said,Chamonix is in a league of its own regarding difficulty.