Snowbird is a vastly superior mountain to that of Keystone-which is an icy hill with long lines. The mountain has epic lines, chutes, wild lips, open faces, so-so trees, fun gullies, etc.
As mentioned, the nightlife at the bird is somewhat limited; yes, you have bars and resteraunts but it is not going to have the options of say, Park City (lamest resort in Utah, for the record).
I'd look at going to Powder Mountain honestly over any of them-and no matter what, go to Snowbasin.
Also, our avy conditions are dire. Do not go out of bounds on your trip, it's not worth it (we lost a girl yesterday to a slide).