I'm a 15 year DC user, and I'm sticking with it. We have a 30ft trailer coming in at 7800lbs on the scales, and the dual cam is the only reason I attempt pulling with a F150.
I have to almost jacknife to get into my driveway, and I've never lost a bar doing that move.
That said... in 15 years I've lost one bar and one cam.
The bar was lost in transit back in 2004 or 2005. I called Reese to order a replacement, and they replaced it at no cost and also sent me a redesigned head as well.
Last week, I lost a cam between gas stops. There's no thread left in either of the holes where the bolts were, so either there wasn't much of a thread to begin with, or there was a force strong enough to strip the threads and allow the bolts to drop. The cam itself stayed attached via the chain, and there's no visible damage from having hung freely for however long it had been free, or around the bolt holes.
Once a set of rivet nuts arrives, that cam will be back on the frame and I hopefully won't need to think twice about it for another 10-15 years.