The shoe as a whole functions very well, I think the sizing is just slightly larger than sidi. I take a 41 sidi, size 8 street shoe, and in a 41 in these i don't think it fit quite as snug. They were stiff, which is good, very cool and breathed well, which is good most of the time. The downfalls for me was that I had to cut the end of the strap off, it was to long and would hit my crank so i just took some scissors to them and now no problems. I don't think the toe box is tight enough for me personally I like a pretty snug fit and had to strap down pretty tight to get it how I wanted it. They went on and off very easy as a tri shoe should. hope this helps some of you out.