First, I love these.  They are super comfortable (I am a 180lb female with bad feet/knees and a wide foot who stands and walks a lot).  That said, I used up my original pair which were a 9 regular and I am coming back for a 9.5 wide as I like to wear thicker socks when it's cool/cold/rainy out and that's when I wanted to use these the most.  I wound up having to wear very thin almost nylon like socks with my 9 regular pair. They are GREAT for outdoor concerts in the mist/rain and light hiking.  Get a comfy well fitting size.