My friend lives close to Verbier hence i go there quite often.
First thing is dont be expecting crowd free slopes as its a really busy resort, especially down the bottom towards the learner slopes by Verbier itself.
Verbier town is the most expensive area you will ever visit as its geared towards the hoo ha henrys of this world, (I have seen Lamborginis driving around town) and the restaunts and bars reflect this. Its good that you are staying in Nendaz as its a lot cheaper and more friendly.
However these are the downsides, the reason its so popular is its a great resort for boarding, just stay high and you will love it. Nendaz is great but head over to Verbiers slopes for the better riding, IMO of course.
Cheers! I don't know how exclusive I'm expecting it to be really, but I've been to Aspen and Beaver Creek this season already. Beaver Creek is 'a bit upmarket'. I'm hoping the snow is better than it was in Colorado and also better than it was during the first week of March last year when I spent the week in Flaine.
Still, 3rd March and I'll be getting my fill for the week... See my hint on the good piest (above), its a great run you will have to try!