I bought a pair from Yan Kelly. Rode them about two years (xc). Towards the last 6 months, the rear would occasionally (rarely) slip/pop when hammering hard. It was as if they would slip one engagement point, then carry on as usual.
He also stocks rotaz and I think he'd be glad to talk to you about them. He might even handle warrantee returns for rotaz.
I am looking for a 15mm conversion kit for the Rotaz FD140 Front Hub. In your post from last year, you mentioned Brandon is trying to stock conversion kits. Do you have any info on how I can find a 15mm conversion kit for the Rotaz front hub?