That's my experience with them as well. We got three 10-year-old machines (clothes washer, drier and dishwasher), and they all lasted 10-15 years more with minimal problems, but when a problem did arise, just getting an official Miele rep to look at it was damn expensive, and the estimate to fix it was the cost of a new mid-range machine.
Luckily we found an non-affiliated technician who was much cheaper and got the part from an old machine for a small fraction of the cost.
