Pros: Big, varied terrain, birthplace of ski, food, atmosphere, scenery, transportation
Cons: Sometimes a bit crowded, weather sometimes
Went back last year (living in Canada now since 4 years): it is still a magical place.
Contrary to northamerican resorts and some French resorts, this place has a history: plenty of atmosphere.
As the terrain is really big and varied, you can pass a day of skiing without ever taking the same lift or slope.
Scenery is absolutely impressive (the Alps !) and contrary to east-canada skiing, temperature is always supportable.
Another great thing: public transportation always gets you back to your hotel, even if you ended up far from your starting point at 16h00.