I am a US size 7 (took me a while to figure that out actually being a UK 4 - 4 1/2) usually but have often had hassles with this type of shoe being a little tight as I also have very high arches.  I had not a one of these issues with these shoes.  They fit perfectly and really look very very nice with everything I have ever worn them with and of course the Eco considerations were what attracted me to them in the first place.  I have paid a lot more for a lot less of a shoe before so I feel rather smug and "green" when I wear these :)