What's your general experience with OEM service centers? I've had two experiences:
1. My Rolex just stopped running after 14 years ( I know, I waited too long....). I sent it directly to the service center in NY and it came back looking awesome and has been functioning flawlessly for 5 years. Expensive service but worth it.
2. My wife's TAG Carrera was gaining 5 minutes per week. I sent it to the authorized service center in New Jersey. It came back and was now losing 5 minutes per week. I returned it: they serviced it and then is was gaining 10 minutes per week. So I emailed the VP of TAG in Switzerland directly with the story... and he just referred me back to the NJ service center. Since my wife is perennially late, we left it as is (better to be fast than slow).

What's your experience with OEM service centers?