Well Keystone the resort is an excellent part of Vail Resorts. I recommend riding there. But not all recommendations are based on the skiing/boarding. Sometimes they are based on the performence of the staff.
2 years ago I took a little trip to Summit County with 8 friends. 1 girl broke her wrist and another broke her arm within 2 minutes of each other on seperate runs. Ski patrol was organized and responded with excellence. The staff at the clinic was helpful and treated us well.
I recommend the resort because it is great riding, but also because its patrol staff is some of the best I have dealt with.