I've had a pair of these (women's version) for over a year now and LOVE them. They still look and feel exactly like new, so they hold up well.
- super comfortable
- better footing than conventional shoes
- surprisingly good arch support for such a lightweight shoe
- they're just fabric between the toes, so not waterproof/rainy day shoes (although they'd probably be fine if you *intended* to get wet)
- if walking on small gravel, it may tend to lodge in the soles
- toe socks are expensive
I've got friends who have tried both these and their 5-toed competitors, and they say the 5-toed ones are superior, but for my money I'm very happy with these.