I've never stayed at the Reef Club, but I've eaten there, and I'd have to say I was not impressed. But to address your points:
Great Beach: Yep, I'd hasve to agree.
Away from the big crowds in San Miguel: That's not necissarily a good thing. Yea, when there are 6 cruise ships in town there are a fair number of people there. But Cozumel is not Jamaica. Even with the cruise ships there is still something quaint about it. Also, IMHO, Cozumel is one of the best eating destinations I've found. There are some truely wonderfull restraunts there and they are cheap. I think it's a good thing to be within walking distance from town and if you go AI, you're cheating yourself.
Close to reefs: No doubt about that. They are a very short boat ride from good reefs. But I like fast boats so for me we're talking about a difference between 15 minutes and 5.
Inexpensive: I can't comment on that I've never stayed there. If you're doing a funjet/apple thing then maybe they are when you factor in the cheaper charter air. My place charges $65-$75 a nite...
James