I think the difference between the Community Hall's and the common rooms are the daily scheduled activities.
When we were at SSR in Dec 2004, at checkin, we received a calendar with the CH activities listed for each day. The CH's are staffed continuously and often when we stopped by, they had cookies out on the tables, video games, ping pong table, books, games, movies as well as the scheduled daily activities some of which required a small fee for supplies (like decorate a mug and the mug was $4).
SAB normally has a recreation CM that will lead the children in Pool Games or other Pool side activities. We enjoyed a game of Beach Ball volleyball there last year, but that is only like an hour a day and nothing like a CH.
I dont recall any organized activities at VWL, but you could check your kids into the Cub's Den for a fee and they have activities there.