Hi Dave,
Our W3933 had a bearing failure at the 8 year mark, under the quality guarantee, Miele attempted to replace the bearings and when it failed again they replaced the spider, backplate and outer tub all under warranty. The Machine is 10 years old now and still ticking along with no other service.
I do think the W3XXX series was the beginning of a decrease in Miele quality. Between multiple houses we have a fleet of W2XXX machines that are now all 10-14 years old and other than a shock absorber replacement on one of them, the rest have needed no service. I've purchased a few W3XXX machines online not working and they've all had bearing failures, plus the W3XXX series was the first one that allowed a cold wash on cottons which has resulted in most of them being crazy mould factories. There is probably a correlation between those things.
My experience has been that you need to remain firm but polite and in most cases they've helped me out. I've pursued them over rusty racks in the dishwasher and always I've ended up satisfied with the outcome. The challenge is when a wear and tear item actually fails then the cost of repair is greater than the value of the machine.
Cheers
Nathan