I use them a lot and always very helpful and the thing I like is the same engineer will always work on my car - he therefore gets to know my car and me - you also get to see the car being worked on, were at dealers which I used before the car disappears into a unit and then isn't seen again until you pay
Another great point is if your waiting you have various great sound tracks from the different cars and a great library of historic Maserati and Ferrari books to read