Every instructor is different than another in terms of their classes.
Find out who will be the primary instructor and talk with them. I think I scheduled my ow class based around time constraints and price when I was looking, I didn't know any better. One of the first things I would have done different is spend 10-20 minutes talking with the instructor, just to get that first impression/gut feeling. If you don't like standing and talking to the guy, you are not going to enjoy the class as much.
BOW (Basic Open Water) Training is going to teach you primarily how to put together your scuba rig, how to put on all of the gear and what it is called, what to never do in the water, what to always do in the water, what to do if something bad happens in the water or at the surface etc. Your first open water dives will be to 15-30 feet and you will probably, regrettably, kneel on the bottom and perform skills like how to recover a lost regulator, how to flood and clear your mask (primarily clear in the event of accidental flooding, but you'll have to learn both), how to donate air to a buddy, how to receive air from a buddy, and a multitude of other little tidbits like how pressure affects nitrogen, and how pressurized nitrogen affects the human body.
In the end you'll feel much like the student of skydiving getting set in the door for that first static line jump. You won't be ready for 60 seconds of freefall, you won't be ready to dive to great depths. You will understand what it takes generally to participate in this sport. Many divers go their whole lives diving at this level in lakes, quarries, oceans, etc. Some go on to advance to levels where they dive wrecks, caves, under ice, etc. You will need to dive at the entry level, build confidence, gain experience, figure out what else (if anything) you want to do in diving and pursue that. At that point who your instructor is becomes much more important.
There are ow instructors who emphasize the lost art of neutral buoyancy, there are unfortunately a great number that describe the state of being neutral and send you on your way. From an unbiased opinion I'd rather learn to dive with an instructor who showed an intention to teach every student to achieve neutral buoyancy, but I wouldn't be surprised if you have a tough run of that. Just understand that price does not equate to service, and while you will learn all of the skills required by the Recreational Scuba Training Agency how much opportunity you are given to learn, understand, and begin to internalize these skills will certainly vary.