I wear a size 7.5, so I ordered a 7.5, the size fits. However, I have narrow feet, so it's a bit wide in the toe area, but overall very comfortable. One of the best Adidas shoes I've ever had.
Pros
I took half a size down and they still fit the big ones, otherwise the shoes are fantastic, just wish they were a tighter fit.
Cons
The fabric on the top can stretch and lose its shape over time.