I tried on a pair of Keens at REI, and the salesguy said he thought they ran small. I had to buy the Seattles I wanted (the urban assault Mary Jane style) one size larger than I normally wear.

When I was trying them on, another woman was doing the same, and absolutely could not stand them because of the high arch support. She said she had very flat feet. I have very high arches and they support my feet like no other shoe. Go figure.