Bristol were ace, got all 13 first time round and 99% in Heli POF, Feb Mod one and May mod 2 feedback was excellent, I would go as far to say they were easy, if you put in the work!
Mike Burton did the Heli instruction, but I think he might have left, so check who they have there now, plus if you decide to use them visit the Heli Museum at Weston during the brush up, make a lot of the theory make much more sense, plus it's interesting.