from what i remember...
i did a spring ski trip about 6 years ago and stayed at the silvertree at snowmass. nice place, ski in-out. there was a small "village" there-restaurant and shops- at the base- not much there, but nice. from there you could take a bus to aspen, which was more of a "town"- more shops, restaurants and a few celebs floating around. to answer your question, i think aspen has more to offer than snowmass in that respect, but skiing snowmass sticks out in my mind and the silvertree served us well. obviously in august that's not what you're going for, but that's all the feedback i have for you...enjoy your trip!