I've been going to ADS for a little over 3 years but have taken more vehicles up there than most people do in a lifetime. They've done everything from simple oil changes to complete rebuilds and have never had any issues with the quality of work that was performed. It's a 1st class facility with a 1st class staff. It would be pretty difficult to build a facility like ADS without a lot of repeat customers. Their customer base covers those that just look at a vehicle as something to get them from Point A to Point B (like a Prius owner) to those of us that enjoy everything related to automobiles and can't leave anything stock (and wouldn't be caught dead in a Prius). They maintain some of the nicest car collections in the Phoenix area.
It's very surprising to me that their reviews aren't 5 Stars across the board but there's usually 2 sides to every story.
M