It's a good idea to replace the brake fluid. That said, I have never replaced the fluid in my 28 year old Blazer. I have not had any problems. But a Mercedes is a Mercedes. And yes, this might well be a "Mercedes thing". Your call. With a power bleeder only one person is required to do the job. Keep in mind, it is a simple, straight order job. Only MB can make it as complicated as, say the middle east situation. Perhaps the Chrysler folks will help in this area as they slowly intigrate their cars/parts into a formerly pretty nice product. For real confusion, buy a BMW.