Mercedes Motorwerks is pretty good too. Very friendly family-owned business. The owner is a real nice guy, too.. and they have an utter ton of W123's, and W124's parked out back, for repairs & some parts.

The only reason I prefer Autobahn Automotive, is because two other diesel-heads in my immediate area reccomended them to me first.. and they get the job done at a good pace.

Either way, you can't lose with either one of these shops. While I can't speak for Motorwerks, I've heard they do some great work.