Big SkyI've been two times and it's one of my favorite places for this reason:
For a major resort, the people per acre ratio has to be the lowest I've personally encountered yet. This is true even on weekends.
The rocks, they are a problem, but just keep an eye out and/or use rental equipment. Their snow cover was not that good last year, but still fine if you use some common sense.
There is no ski town like a aspen or breck. But I wouldn't personally do that drive back and forth to Bozeman each day. You can get reasonable rates at the comfort inn or best western at the bottom of the access road. Personally I'd just rent a small car rather than the shuttle just to have flexibility not having a real town there. There is an up and coming start of the access road village that has more each year then about 10-12 miles up the access road is the resort village proper. Having a cheapo rental gives you more options for the evenings. (or for a side trip to Bridger)
There are lots of condo's in the village. Last time I stayed I stayed walking distance from the slopes at a privately owned hotel accross from the huntely.
I'm going again in February and it's on my do once a year list for sure.