Returned yesterday (16th Feb) after a week long stay in Flaine (w/c 9th Feb) and had a great time. The snow was great quality considering it hasn't snowed since the 6th Feb now, the sunshine was fantastic - even got a tan whilst there.
The resort itself offers lots of steep groomed red runs perfect for the talented piste skier, very few black runs on offer for the more demanding. Also not a great deal of green runs in Flaine itself for complete beginners, the 2 accessible greens were always packed.
If you're taking children be wary of the ski school, they seem to have no problem packing as many as 16 kids into one class - imo far too many. In the US there seems to be a 7 max limit. The ski-school itself was very serious for children, compared with the US schools where the emphasis is on fun it was a little odd to see my cousin pushed so hard on skills for a child (9) - he didn't want to go back for his 4th or 5th lessons (and didn't), I imagine situation is better in off-peak though.
Food is very expensive on the mountain, a couple of steals to be found though if you shop around the on-mountain bar/restaurants. After skiing restaurants are nice and lively but family oriented mostly.
We took a snow-shoe walk on night for a couple of hours which was absolutely fantastic, seeing the back non-skiing part of the mountain in just the moonlight is well worth the money (something like e35 each including delicious 3 course dinner)
High Intermediate: 5/5
Ski School: 2/5