Not directly Challenge-related although I feel I should bring my experience of good after-sales to the attention of Challengers & backpackers:

I badly damaged a sleeve on my trusty Rab Photon Hoody jacket a while back and carried out a temporary repair with patches of Tenacious Tape.
The repair worked but didn't look pretty and I wasn't convinced it would last too long before failing.
I sent the jacket off to Rab who carried out a swift and very professional repair for the princely sum of £30 which included shipping back to me on a Next Day service.

I'm impressed - just a shame that Rab are no longer involved with the Challenge.

I can endorse that. Zip broke on my Down jacket, sent it back and returned with new zip foc. Great service, it was under warranty.