Love the Bird. The combined vertical and quality of the snow is some of the best I have ever seen. Chutes, chutes, and more chutes. Most of the side-country is accessible by lift plus traversing, more by hiking. Lots of hidden stashes all over the mountain. Even at 3:00 you can find near-untouched pockets. Mineral Basin is subject to closure a lot, and may be the most unpredictable place on the mountain. It can be incredible one day and forgettable the next.
Everyone on the mountain is courteous and respectful, which is a nice change. No clowns who mess with your line, stop in the middle of runs, or use you as a gate in their imaginary super-G. As for crowds, its all relative, but I have never found myself complaining about wait times or overcrowded runs. Plus, because Little Cottonwood Canyon is avalanche-prone, the road in will periodically close, meaning those at the resort get their own private sessions with hardly anyone there.
Family friendly? I guess, as long as your kids can ski or ride. I saw a lot of families, but most seem to be connected to the ski races that were happening that weekend. Its a mountain geared for experts who want to ride more than hang out at the lodge.
There is no real nightlife at Snowbird. Its not a resort like ones at Park City or Tahoe. More of a "hanging out in the hot tub with a beer" and less of a "drinks at the club" type place. This is probably a good thing as you do not want to be hung over for the first tram. The amenities, however, are spectacular.
For perspective, I am a boarder who spends most of the season in Mammoth and Tahoe. While those places are bigger, the Bird is better.