In reply to mikekeswick: Hi Mike, Not sure if you're based in Keswick or not, but I popped into Planetfear in Keswick a few months back and picked up both the 190's and the Barefoots.
Completely different shoes.
The barefoots are completely flexible - you can bend them double very easily. There's no protective midplate thingy in there.
The 190's (which I'm tempted with) are a light shoe with protection in the midplate thingy. Yes, you can bend them double but they aren't as floppy as the barefoots.
Not sure if you've run in barefoot shoes at all - I've for the New Balance Minimus which are great - but I'd hate to do a pebbley descent on them like Iain mentioned above. Just torture. The minimuses are completely flexible like the barefoots.
I think the difference comes down to this midplate protection thingy. It's effectively a protective layer of sorts between the upper and sole which shields out the worst of the pebbles etc. Personally I wouldn't run on rocks without one which is why one guy mentioned that on anything but grass they will be shredded.
You didn't mention what you currently run in. I use Walshes and love em. Minimal ish with great grip. They've given me a good forefoot technique anyway so my switch over was relatively problem free.