See a recent thread on aeros generally:
http://www.pprune.org/dg-p-general-a...aerobatic.html
I did my initial aeros endo with Red Baron and can honestly say it was some of the best training I've received. Knowledgeable instructors with good briefing skills. Support material for key concepts. Actually cared that I
understood the hows and whys of what I was doing, then made sure I could explain it and demonstrate it. That was three years ago and I unhesitatingly recommend them to anyone. If I was being paid more, I'd still be out there every weekend!