OK, so I actually got a pair, 'cause running barefoot through downtown portland is a little sketchy. They are actually excellent for running. Basically, you very quickly learn how to run properly, using your arch as the shock absorber it evolved to be. I got them because pretty much every running shoe screws your stride up more than it helps. Sadly, after 30+ years of western culture shoes, I still only run <10K in them.
Your lower legs get worked more, but it feels good. My knees get less achy from miles.
They don't do well in mud and you have to watch your step on sharp basalt gravel.