I don't get it. I am no orthodicts(sp?) expert, but that can't be good for your feet. I understand it might be comfortable walking around but running? I see feet and back problems in the future. Oh wait it is like SS, we will all have knee problems at some point.
The premise is that the body is structured for a certain type of gait. Your heel bone is relatively porous and can absorb a bit of a hit. Your tendons, the muscles of your feet all work in controlling your movements and influence the movements of your legs. Modern running shoes provide a lot of cushion and limit the muscles/tendons in a foot to develop, which makes your foot, the conduit between your body and the surface you are running on the weakest link.
As a runner, I had fairly regular injuries- Achilles tendinitis, inflamed plantar fasciitis, etc. I read a couple studies and switched to racing flats for all my runs and never looked back. Less cushioning made me modify my stride, as the heel strike that I was accustomed to kinda hurt on pavement and I actually got faster- so I turned into 7:30 pace time for long distances, 6:30 for shorter. Not bad for 200 lbs monster.
You might have a different experience, but they are a good/great idea and I hope pnut loves the **** out of them. They just aren't as cool as Roos, even with the strap issue.