2012 157 T-rice or 2012 156 Custom flying V?
I have only ridden the T-rice three times here in the east coast and it was awesome on the hardpack, icy runs.
I have yet to ride the 2012 custom flying-v.
I used my retired 2010 Custom V-rocker last time I was out west and it was adequate.
I suggest trying out the Custom flying-V on hardpack and see how you like it. If it sucks, and conditions in Whistler are the same, then go with the T-rice. If it's powder, figure out which one has better float and take that one with you.