I just sold my nexus 3 c/b a few months ago. It was used lightly for a year then was used alternatingly with other bikes for commuting for two years. It was then used for trail riding. I was a clyde during that time and also had enough power to take a 44/18 singlespeed up a 10% slope.

The hub held up fine. It braked and shifted like new when I sold it. I had to respoke the rear wheel but the hub was fine. I pitted the front cones and wore out the bottom bracket and a set of pedals.

I am not trying to use a bit of hyperbole here. The bike was basically a $109 walmart special and the spokes, bearings, bb, etc may not have had the best materials and adjustment.

So, my nexus 3 c/b held up over three or four years of sometimes heavy use and worked when I sold it.