How about Light cycle carbon wheels?
Lengthy threads on MTBR don't seem to point to any issues with the company's products. This one is about the wide 26" rims. I have a vague plan to get a pair of the rims and lace them to the hope xc hubs I have looking for a job.
I am currently using flows on dt 240 and can't fault them, but I have always had a hankering for a set of crossmax sx. A friend has been using the same pair of crossmax wheels (xl, I think) for years and they just keep on going. I also like the look of the Syntace wheels that should be out soon. Cheaper than carbon, but light, stiff and very wide.