I think cranham gives "more bang for the buck" as the yanks would say. A lot of MTBing these days seems to be focused towards getting as much technical / fun riding as possible in a ride. I know if I want to get someone interested in MTBing Cranham is the place to go – although only in summer.
I suppose those trail pixies who put in the Cranham runs are a victim of their own success as no where in the Cotswolds has as much quality riding in a small area. (Big thanks to the pixies by the way)
I've wondered if perhaps during the winter if trips further afield (Dursely, Malvern, Bredon etc) would open up more options for riding if everyone is bored of local places.
There are some great routes round here but I think people are becoming less focused on putting the miles in and more focused on the fun factor which leads them to aim at cranham.