I have the Shimano Afline Dynohub (dsh501) and it has about 10,000 miles on it. Commuting, touring, singletrack and some epic 55 mph downhill runs in Colorado. Recently (last 500-1000 miles), it developed a pretty strong humming noise when I get to about 25 mph but it still works. The right cone nut came poorly adjusted from the factory/wheelbuilder and fouled out at about mile 5,000. I replaced it, which was quite difficult. No shop was able to order it locally, I resorted to importing it from the UK.

Also, overhauling the disc side bearing is a real PITA. It is much better sealed than the right side. I've changed the balls/grease 2x since I got it about 2 years ago. The hub has survived being submerged in FL swamp water and mountain stream water. It's not perfect but for most riders who aren't too demanding it's priced just right. I will probably get a SON hub in the future if/when this one kicks the bucket. Loose ball bearings are tiring to maintain.