Having skied both UT and WA snow extensively, here's my $0.02:
Interior snow is dryer, and in terms of powdery goodness during turns, it is nicer. However, I much prefer PNW snow for a couple reasons.
First, PNW snow is more dense and provides a much better base underfoot. Unlike interior snowpack, you aren't constantly questioning whether a landing has enough coverage. If its white, it's right; assessing a landing is only a matter of inclination/dodging bomb holes and trees, whereas with interior snow you're constantly looking for clues hoping that you won't be impaled on jagged rocks anytime your hit a cliff larger than 10 ft. Second, denser snow is nicer provides more cushion in landings. Instead of punching through dry dust to the rocks, you have some wet snow underneath to fall onto.
The hype revolving around dry powder in UT is largely based on old farts who only make turns and never send big airs. Also, the difference in snow quality just for turning is horrendously exaggerated for some reason. The only people complaining about PNW snow being "heavy" are tourists who suck at skiing.
In my mind the PNW has the best skiing in North America aside from Alaska and Jackson Hole, both of which are so damn gnarly that it often takes away from the fun.
