I'm fairly new to cycling, but these bibs have been great. They've ridden with me over 500 miles on a mountain bike and show absolutely no wear. This is even more impressive as I have had several hard spills on the single track. Every time, I have scrapes on my calves and arms, but have amazingly escaped with only bruises (some very ugly) where the bibs cover.
I've also been impressed with the chamois. It was a little uncomfortable at first, but after just a few rides, it got broken in and is comfortable enough to walk around as well as ride in. The longest ride I've taken is a 4-hour jaunt up a local mountain and back. Chaffing is something I worried about, but has never been a problem... not even a little bit. (I've considered running in these as my running shorts can't brag the same track record.)
Overall, I recommend these and will probably come back to Fox when it's time to purchase new shorts.