I've been bringing my VW's here for nearly 8 years...first my wife's 99 passat wagon and my 04 passat. Last year, we bought a jetta sportwagen from them, largely because of the quality of the service we've gotten from the service department.
We've had to face some pretty large repair bills at times but, I've felt they have been fair and done quality work. There have been a few hiccups but, the service folks have always been accommodating and flexible to help work through things.
I have tried taking my cars to other shops a few times but, honestly, the price savings weren't that great and I have received more reliable service from the dealer....
hint: If you need a lot of work done, plan ahead and ask for a loaner car. They're usually really good about that