We are planning a ride this sat to dalby forest to sample the delights!!!! But i heard of a friend that you now have to book in advance!! I have heard its popular but surely not to the extent where you have to book a slot etc.
That's just silly. The car park is a bit reduced at the moment as they're fixing part of it up, but there's some overflow parking signposted.
It does get busy there when the weather is good, but many people are there doing family stuff other than biking, and even when it's busy there's plenty of room on the trails. You would need to pre-book the go-ape highwire thing, but I doubt that's what your mate is talking about.
Go there and ride the red route as it's really good and mixed. Nothing too technical and a decent length at ~ 22 miles.