We were based in Vallandry, one of the villages of the Les Arcs ski resort. I thoroughly recommend staying there, as there is now a superb gondola across to La Plagne which takes a mere 3 minutes or so. As a result you can get across the valley early in the morning with minimal hassle.
We did 5 days in Les Arcs and 2 days in La Plagne. Helen and I had been to La Plagne 2 years ago, so it was good to revist it. If anything, the snow was better there also. The first of the 2 days in La Plagne was a full one, so full that we missed the last official gondola back across the valley, however, we managed to get onto the service gondola for the staff, and quite a lot of other skiers/boarders by the time it left!
The tree lined runs directly above Vallandry were excellent, as were the descents off of the Aiguille Rouge. However, my favourite was probably the run below the short 2300 chair. The reason being that from the top you could hammer straight to the bottom in no time at all. The chair lift was 700m long, with a descent of 175m. Only timed a couple of runs one day, and managed 34 seconds. It meant that from the point that your backside left the chair at the top to the point that you sat down again at the bottom of the chair, less than a minute would have passed. Sad, but remarkably good fun!
One of the attractions for me about Les Arcs was the flying kilometre run. Unfortunately, i hadn't done my research, and didn't realise that it doesn't open until later in the season. By the end of the week i had a miserable cold anyway which would have probably stopped me trying it. Maybe another time.....