I bought these a month ago. Last weekend, I ran my first marathon in 3:07. It wasn't all the shoes, but they definitely made a difference. These are incredibly light, and they make going fast seem easy. Would highly recommend.
I used to always run in barefoot shoes - ones with toes and without - because I liked the lightness and the feeling of connection with the road. But for long distance, I could feel they weren't good for my back. These give the same magic of running barefoot, but with the added benefit of some spring.
I usually run in UK size 8, so I bought that size. Initially I was worried they were a little snug, but I decided to give them a go without socks, and after a few miles they worked into my feet, and now I think they're the most comfortable shoes I own.
These deserve every accolade. You won't regret buying them.