As most reviewers have stated they do run small. I usually wear a 7.5 - 8 in shoes but size up to 8.5 in sneakers because of wider feet. I ordered a size 41 and they fit perfectly and are comfortable.
I used it in my spin class today and they made a big difference. Im still getting the hang of how to clip them in and out.
They do not come with cleats you need to purchase them separately. But the price for this shoe is way better than the stores I looked at.