I just got mine in brown and wore them all day with very little time to break in.  My normal size in dansko is a 38 but in the ryder bootie the 37 was definitely the better fit so I say they run a 1/2 size large. I also needed the support that Dansko offers and LOVED the ryder bootie style that is so versital it can be worn with jeans, skirts, dresses, cropped pants and kakhis! I also purchased them in "used" condition but there wasn't even a scratch or scuff on the soles or anywhere else!  Saved Tons over retail!  Definitely would purchase via Amazon again!