The roaring fork valley(Basalt),is one of the most beautiful places in Colorado second only to the San Juan's. As as size, it's small, but Aspen isn't far away neither is Glenwood Springs. As far as rock climbing, Glenwood has some, Aspen has some on Independace Pass, both 30+ min away. Ice in the winter is great, and skiing can be world class.
I've never been to Bozeman, I've heard it's cool. I love this valley, but it has some major downsides, one is it is very expensive to live here and I'm thinking about leaving for that reason. It really depends on what you are looking for. Climbing here, though stellar in some spots, I.E. Rifle and Indy pass, is a trek to get out to, there is closer stuff to climb, Frying Pan in Basalt, Red stone boulders and some interesting secret climbs as well. If you are looking to climb Ice I think MT is the place. There is great skiing here (Last few years have sucked for snow.) Great Mtn Biking too. I love my community here- although it trends to be a mid thirty something or older crowd and if you are single, good luck, not great odds for dating- great people here. If you do come to the area, Carbondale is waayy cooler than Basalt. I hope that helps, good luck on your quest.