I also used the $9 Oil Change Livingsocial coupon and had no problems. I took my car in early Saturday morning when they weren't as busy (I also made an appointment). They told me they would be done in about 45 minutes and they were right on the mark. They also did a general check on all my fluids, etc. which I don't usually like because they tend to try to sell you more services afterwards. This place did not try to push me into buying more services, which I appreciated.
I did end up paying $6.18 more in taxes, etc. which brought the total oil change to about $15 ... not the greatest deal in the world but overall I was satisfied that they did the job and didn't cause any additional problems with my car.