I have skied Kicking Horse one day in the very good snow season of 2002. When I was there you had to ski the whole 3,800 gondola vertical each run. The lower half of the mountain gets much less snow and it has often been reported thin (or restricted to a couple of groomers) in the past couple of years. Since I was there the Blue Heaven chair as been added, which allows you to run laps on about 1/4 of the upper terrain.
As one who been doing advance plan destination trips for a long time, I must disillusion some of you regarding powder. The probability of hitting a big dump (say 1+ foot overnight) during a one week advance-planned trip is probably 10-20% at best at most destination resorts. Even at Alta/Snowbird it's probably no more than 40%.
The probability of that dump is definitely higher at Tahoe than at Kicking Horse (I'd guess 30% vs. 15%). Hamdog is certainly right that if you get that at Tahoe you'll have one day to enjoy it vs. several at Kicking Horse. Without fresh snow you're better off at Tahoe with the big snow base and variety of terrain this season. So, to paraphrase Dirty Harry, the question is, "Are you feeling lucky?"
This goes to a general philosophy of what you want out of a ski trip. I believe the first priority when shelling out the $ is to avoid big mistakes, primarily unskiable terrain due to inadequate coverage or snow conditions. Fresh powder is a lower priority since you're not going to get it most of the time anyway. Many FTO readers may disagree with these priorities.
I love powder as much as most of you, but after a powderless 1995-96 I came to the conclusion that if I had to have a powder fix, the only way to give that a high probability on a destination trip was to go cat or heli-skiing. I have therefore done 2-4 days of that most seasons since.
The best way by far to maximize powder is to live within day commute distance, so you can cherry pick your ski days on short notice instead of making advance commitments. That's why Mt. Baldy has 4 of my top powder days (
http://bestsnow.net/vertfeet.htm ). Our esteemed administrator has figured this out and chosen his new residence accordingly.