Having had the chance to travel to British Columbia several times, I have also had the chance to visit Whistler some times as it is located in this region. The memory that I have of it is a little ambiguous.
On one hand, the setting is exceptional, situated in a grandiose landscape, and the infrastructures are of near-perfect quality (thanks to the regulations of the Olympic Games!) The resort is very popular with sports fans due to its main attraction: skiing of all possible types and varieties.
But, on the other hand, the constant mass influx and the terrifying price of life there (a lot higher than some well-known French resorts) give a certain elitist feel to the Whistler resort. It's necessary therefore to plan a certain budget to fully enjoy all of the attractions offered by the place, and to not hope to find a strictly authentic experience of Canada there...