I've tried a couple of Xero shoes. The running shoes I got (can't recall the model name, sorry) were _very_, _very_ thin-soled. You're probably used to low-drop, but these are a step beyond. Not recommended on pavement, and require an adjustment period even on dirt trails. Even though I don't wear them very often (lots of pavement around me), the soles are starting to wear out. I believe xero makes some heftier shoes designed for trail running, but I was trying to find out just how close I could get to "barefoot", and the answer was: only in ideal conditions. As an everyday sneaker and for most of my running and hiking, I'm back to wearing Innov8 (Roclite 275, I think).
I love Xero's "barefoot" sandals ("Genesis" or "Cloud") - they weigh nothing, take no pack space, are comfortable, and let my feet breathe. Not enough support for soccer or hard running or tricky ledges, but for stream crossings or around camp, or crossing the hot part of the sand for a day at the beach, they're great.