I’ve just built a set for myself. Only fitted them to my bike last night so haven’t ridden them yet but from a build perspective they are very impressive. The offset spoke bed evens up the tensions side to side and makes for a really nice and stiff build. Rim weight is near-as-damn-it the same as a Flow EX (mine were 8g lighter than a Flow EX).
I’ve also built a couple of pairs of the Trace Trail in 650B and I’m part way through a 650B set of Enduros.
The 650B Trace Trails have been being ridden a fair bit and are working well.
Tyres went up tubeless really easily with a trackpump too and the width of the rim creates a nice rounded profile.
So far so good