Not at all! And you absolutely should. All surgeons should have a referral list of prior patients to discuss particulars and trade stories. I personally spoke with patients beforehand and as a matter of fact am on my own doctor's referral list.
If you are wondering if all of the patients are going to be happy or receive compensation... I have found in my experience that there are about 1 to 2 patients who wish they had done more research beforehand or had gone to another doctor entirely so be advised that although this is unfortunate I think it is helpful to the patient considering the procedure to gain a well-rounded opinion.