These shoes are awesome! They look really cute with dresses and jeans. When I first got them, the backs rubbed my heels a bit but since I've broken them in that hasn't been a problem. I usually wear a 9.5 or 10 and I got the 41 and they fit great.
The one potential issue is that they don't have much arch support. The bottoms are nice and soft & comfortable, but after wearing these & walking around for an entire day my feet did start to hurt. I am someone that needs a lot of arch support though. If you don't normally have arch issues you should be fine!