Keystone & Breckenridge?

Our family is planning a vacation to Colorado for the first time at the end of March. We have decided to stay at two resorts, Keystone & Breckenridge, because of the additional activities they offer (like ice skating, tubing, sledding) for the non-skiers. We have 6 nights and 7 days to split up between the 2 resorts. My 5 year old daughter and my husband will be skiing 3 days during the trip. Can anyone suggest how to split our days up among these two resorts? I am not familiar with these places, I only know what their websites tell me so I don't know if we would be better off staying the majority of the time at one resort versus the other. Any suggestions from those of you that have skied these places would be great!