I have found that most poor quality equiptment come with the best warranties.
Warranties have very little to do with quality. They are a marketing tool. You can see this even from MB. They give all their rebuilt items at least the same if not more warranty. I think they warrant rebuilt engines the same as new cars now. A new short block probably has a one year warrantee as they know it needs none.
Take places like AZ and you find lifetime warranties. You might expect my opinion of most of their parts.
They do sell some Bosch though and if they warrant it for life more power to them.
Bosch Master, ASE Master, L1
33 years MB technician