I go to CU as well and split park and "big mountain" about 50-50 as well. I grew up in Colorado and have skied the epic pass mountains for many years.
Keystone - A-51 park is great. Quite simply, anywhere else is not so great. A few fun hits scattered around but meh overall.
Breck - I don't ski Breck that much, but they have a phenomenal park obviously. Rest of the mountain is pretty fun. New peak-6 hike-to terrain is awesome. T-bar/horseshoe bowl is solid as well along with lake chutes and peak 10.
Vail - Best resort to ski entire mountain consistently, best areas are cliffs in and around Northwoods and Blue Sky (cliffs, trees, steeper runs). The bowls are overrated in my opinion, they get crusted with any sun, are typically windblown, and visibility can be pretty poor often. Worth mentioning is chair 4 cliffs/jump, cliff band isn't too great for me (short tranny and taking a tumble can be real dangerous), but I love the jump - usually by mid season it's prime and I've seen some dubs on it. Gold peak park is underrated, not very crowded, good rail garden, decent jumps.
Beaver Creek - Quite boring overall. The one place you need to go is Stone Creek. Great cliffs and pillow lines, nobody skis there, landings can be nice for a while although warm weather takes its toll there. Park is alright, hit their park once this year and jump shaping was quite different.
A Basin - Last but not least. Nice long season, good terrain, and no security. Unlike 95% of Summit, Pali is actually steep so it's nice for pow days. Zuma cornice and East Wall are worth mentioning.
Now... traffic. I honestly don't think it's as bad as some people make it seem. You can navigate I-70 easily if you plan a little. I'm amazed with how many people still drive at the worst times (6-8 Saturday morning and after 1 on a Sunday). Sacrifice an hour of sleep or an hour of skiing to avoid the traffic. Unfortunately with snow on the roads, accidents are almost guaranteed, this is the worst part of I-70.
Resorts will consistently be more crowded than you are used to. I don't quite understand why Breck is the dominant hotspot, but weekend crowds are notably rough there. Anywhere else isn't too bad (maybe I'm just used to the crowds), resorts are typically twice as crowded on weekends.