I would take CH. Your kids are the same age as mine, and they will have a lot to do. CH is very self contained and I feel very safe there. We let our boys go over to the activity center for a couple hours at a time and didn't think twice. They will also like the ability to make friends and interact with others.
GV is another great choice, but it is huge and there are a lot of people coming and going that aren't staying at the resort (golf, timeshare presentations, restaurant, etc.).
GV does have 2 queens in some of the 2BR units. I had this set up as part of a 3BR with a lock off. We occupied the whole thing, but my son and his friend each had a bed in the second BR.