First of all, Hotel Cozumel is NOT small, it looks small from the street, but is actually a pretty good sized property.
Scuba Club gets very high reviews and much like Blue Angel, has a very loyal following, but I don't think they are quite the same.
It's true, they are both small properies, BA only has something like 22 rooms, but Scuba Club has no phones or TV's, which is fine if you are into that sort of thing.
It has a guarded gate and has a secluded hacienda/resort feel to it where BA has a more inviting, "open" feel to it from the street not so much a "resorty" feel.
Not that Scuba Club is "stuffy" by any means, I get the impression you are treated like family there, just like you are at most the places I have encountered on Cozumel. It just has this feeling of mystery behind those stucco walls and big wooden gate.
Is Scuba Club AI? Or do they offer both? I would also suggest not going AI on Coz. There are soooo many good restaurants, we often are not able to make it to all our favorites. You really do yourself a disservice by just eating at the place where you stay.
Breakfasts and even lunch included is a great idea for dive days, just for the convienence alone, but on those non-dive days, we like to head to Rock-n-Java, Jeannies Waffels or the Museum for breakfast. (the museum is a "must do" for us).