I frequent a dive shop that not only caters to new divers with an in-store classroom and pool but also to tech divers. They are the only shop in the area that does both. The owner and his employees are knowledgeable and very helpful. The shop sponsors trips as well as local beach and boat dives. It is the model all shops should strive for.
At the same time they receive negative reviews from dissatisfied customers occasionally on Yelp. The shop owner replies to every negative review politely and always offer a sensible resolution to the customers' problems. Still, some people can't be satisfied. I have discussed some of the more negative reviews with the owner and employees and it is almost always someone who signed up for a class then skipped sessions or bought an item, used and abused it and then demanded a full refund.