I'm sorry to hear of your bad luck. Maybe I'm due to catch up and the next one will not be good. I usually do not have good luck, so maybe I'm catching up a little.
I'm not totally sure where I got this idea, and I may be totally wrong. I think that the Bosch rebuilds are not done in Germany. They are done by various Bosch certified rebuilders in the states. They are independent rebuilders that are certified by Bosch.
Part of my job is running a program for Certified Integrators. In the software business, the integrator is the one who takes various software products, puts them in a pot and stirs to cook up the end users system. No matter how stringent the testing and certification procedures, some of them will be good and others not as good.
I'm wondering if this is why you have gotten bad ones, while the ones I've used have been great. You may be getting them from someone who is about to lose their certification, while mine have come from another one, who has their act together.
Anyway just a thought. You have me now to a point where I will at least check the MB price next time.
Thanks very much for sharing your experiences,