Valley is pretty good but depending when you go the circuit can be extremely busy, weekends no problem. During the week they have loads of low hours pilots in fast jets wazzing around. Its a training base and a bit different to normal mil airbases. The controllers sometimes won't have a clue whats going on and some would say some of the pilots don't either.
So I would definately plan to not get to near that one and to route round it. But if you don't ask you will never know if they are going to say no. Weekends just check to see if they have a flying program.