If the surgeon and/or his staff give you a hard time or try to convince you RNY is "just as good" or some such rot, remember that the surgery date isn't carved in stone. You have the option of cancelling that date and going to Dr. Ayoola. All of your pre-op testing, psych eval, etc can be transferred to his office.
The only concern of anyone and everyone involved with your care should be what's best for you, the patient. Of course your surgeon should be paid for his time and skill, but other than co-pays that cost shouldn't fall on you, nor should you be threatened with a substantial non-refundable cost over what is a perfectly good insurance code. If your surgery is delayed a month or two because you decide to change doctors, it's not a big deal. You won't be the first or the last person to do this. Living with an inferior operation for the rest of your life is a very big deal.