I run them, and they're great. I'm on my 2nd set now. I bought them at Les Schwab so they came with a lifetime parts and labor warranty (think think the parts warranty is standard regardless where you buy). These were an upgrade from the Monroe monotubes I ran previously, which didn't quite have enough rebound damping, and also only lasted me about 30,000 miles a set. I went through 6 sets of those before upgrading.
Like any single-reservoir shock, it is possible to overheat them if you're doing long high-speed off-road driving. That's how I roasted my first set (took about 15 miles). I've been a little gentler on the 2nd set. I've contemplated a set of remote-reservoir Fox shocks, but since the KYBs have the lifetime warranty, I'll just keep getting them swapped when I burn them up.