This shoe is very high volume. im a 44.5 street shoe, 43.5 in the instinct s (for comfort, 43 for performance) and I got the stix in a 42.5. the length of the shoe was very tight on my toes and heel but there was still baggage on top of my foot. If you have a low volume foot, this shoe is not for you. Also the heel fit is quit strange. the outside of the heels fit snug but the inside portion of the shoe has a huge pocket of dead space. I literally said wtf when I put them on. All in all this is a very high performance slipper that is not for me. very very bummed