I was worried that these might be too small, I used to wear a 7.5, but lately I've had to go up to 8 in some brands/styles.  I did order these in 7.5, and they fit perfectly with socks on.  They are SO comfortable, and pull on and off easily.  I haven't gotten a chance to wear them for an extended period of time, but I have no doubt I'll be able to walk for miles in them!