We did comp crew with them a few years back and could'nt fault it - also did day skipper practical as evening class, I would say that some instructors are better than others - unfortunately its pot luck who you will get!
I have done several courses with them, but it was a few years back, certainly excellent then and I have no reason to believe that they have not maintained their standards. I live locally and would likely have heard if their reputation had gone down the pan.