The hub have 2 years wuarranty or 20.000 k (incluyed the bearings).
I have used twohubs (testing for SP), and I have exceeded 20,000 k using in the worst conditions. So hard than I need to replace before the rim (with 19.500 k) after a hard winter.
Finally I replace the first hub with 25,800 k, until I began to notice slack on the left bearing, while the operation was still correct and electronics intact. .
The second wheel I'm still using, and It's the same that I used on the TransAm Bike race after tested 7.000kms. Actually have 20,580 k and looks nice.
You can send me the hubs (If I sold them) to replace bearings because they are cheap, but I think it's not a good option If you need to pay the shipping cost +10€ by the bearings and 30€ by hand-work.
You can find me on the SP catalogue. :)