These hubs are CRAZY nice, however:
-Rear is only threaded on one side, Not flip-flop. Why?
-No black finish available.
On the plus side:
-The "C-clamp" bearing retainers are quite clever.
-The "multi axis machining" used in the manufacturing process requires ownership (or access to) an expensive and complex machine.
-The brass washer and aluminum "jam nut" seems like a great solution to me, as I politely disagree with Momentum's comment above. It appears that the flange diameter of the brass washer is larger than most hub's nuts with "floating" captive washers, allowing the clamping load to be dispersed across a wider area. In additon to that, the brass washer appears to have a narrow "neck" that slots into the frame's track end, keeping it aligned and reducing deformation of the brass portion.