Of all the mountains in the Vail/Beaver Creek/Breck/Winter Park area, I like Breck the most. Both for the active mining town main street feel as well as the terrain variety and challenge on the mountain. Many people see Breck's wide blue slopes and think of the ski resort as ideal for beginners and intermediates. That is true but Breck also has the most challenging terrain when compared to the other Epic resorts such as Beaver Creek and Vail.
Beaver Creek is very upscale and nice but the terrain variety is not great. That said, you may love it because their customer service is excellent and many people ski/board at a terminal upper intermediate level. Regardless, visit Vail, Beaver Creek, Steamboat, and other resorts before you buy another timeshare.
From my perspective, Alta is the best ski resort in Utah and Breck is the best in Colorado. "best" = combination of terrain difficulty, snow quality, value, and feel. Check them all out and decide for yourself. Remember - buy resale!