I was told when I bought my Hadley/823 wheelset 5 yrs ago that they would last. I have replaced the rear bearings once and that's it as far as major maintenance. I did note the front hub can develop slop, but is easily dealt with tightening the bearing preload bolts. I have done this maybe 4 times in 5 yrs. Besides these two points, I have actually done no maintenance at all on the hubs. (bad bike rider, bad!) Probably the best general DH setup around and maybe have a Hope/Flow setup for race-day if you want.

Built front and Rear on 823's, ride Whistler, regularly throughout the summer and local Dh trails, rebuilt them after one season, bearings started to go.. also had play in the front hub... seemed to be fine after rebuild, but never as smooth as King's or Hope's. Went back to Hope's this season, cheaper and maintenance free..Could be that I'm biased, since I'm English and my last Name is Hope..