Good for XC riding (when its dry), proper long days out and if you dont mind cheeky, then its not all boring Bridleways / country lanes 🙂
I can imagine that a proper cycling club may not endorse riding cheeky.
There are also some good spots scattered about for a bit more gnarr, but sure, its not the FoD. Round the Stroud area there are quite a few good places for getting out of your comfort zone.
It has a steep western edge, lots of rolling hills not too different to the Chilterns and a few spots here and there to entertain you. Lots of nice village pubs to stop in post ride. For a long summers day out its hard to beat for XC.