Alta and Snowbird have a ton of terrain to offer combined. I was lucky enough to have been there only when they had a LOT of snow, one week had 5 feet total. (I have been a lot because my cousin lives in Alta) So unfortunately I cannot vouch too well for what people in Utah would consider a bad day(I'm from the EC though). When it's pretty good snow, the tree skiing is more fun than anywhere else I have been, the steeps are not as big as say Jackson, but they are still there and the mountain is not very crowded at all. There are plenty of gulleys, cornices, lips, and cliffs to pop off too. I honestly enjoyed Alta a lot more than SB, because it was less crowded and had more untouched snow and more fun terrain IMO. The snow anywhere in Utah is awesome and light, better than anywhere else I have been (pretty limited though)and there is plenty to explore. If you are there you can easily make a day trip to Park City, Canyons, Solitude or my other favorite than Alta, Brighton. All of which are like less than an hour away.
PM me with any questions, I may be able to help you out.
Have fun!