This might not work in all locations, but many shops will do some sort of Try SCUBA class and deduct the cost off the Open Water class if you decide to proceed. This allows you to interact with the instructor in a teaching environment and assess the quality of the shops training gear. Not a perfect solution, but you will quickly know if the instructor is just pushing numbers or if they have a passion for teaching, and the patience required to train you as a safe, competent, independent diver.