I had never bought a pair of shoes from the internet, and I probably won't again. The problem is the sizing. I bought what I know is my size (4) but when the shoes came they were far too big. Extremely comfortable shoes with brilliant support (obviously very good for your feet), but the sizing was way out, which meant that they fell off as I walked. The other thing to watch out for with this particular pair, is that the bar across the top of the foot might be a little too far down towards the toe, so even if you do have the right size, check that they won't fall off anyway because of the positioning of the bar. The bar can also cause pain across the top of the foot if you are doing them up tightly to try to get them to stay on.
A mixed review, overall I love the shoes, but was disappointed by the sizing problems. I would recommend getting the size smaller.