I have been wearing Five Fingers since they came out in Australia in 2007.
I remember putting them on for the first time - that was it I was sold they were so comfortable. I remember it took 3 months for my toes to separate naturally they were so used to being squashed together in normal shoes.
Five Fingers simulates going barefoot with protection, whether it is walking or running where there might be small stones on the ground or in the water at the beach.
I wear them in everything but a business suit. They are comfortable, give you agility, sensory perception of the ground and I believe for me better posture.
One downside is that I go through them like rubber on a car tyre, I can go through one pair in 6 months. This makes it expensive. I felt like, and obviously this is just my opinion, that the first pairs in late 2000s lasted longer and now they last a shorter period time. I really hope they didn't change the composition of the material early on.
Otherwise it makes me feel free like I can jump really high.