I did a lot of research before I bought these.  Several people said the shoes ran small, but the majority said they fit true to size.  I purchased my usual 8.5 medium.  After I received the shoes, I found that the left shoe was really small, and the right foot was a little less snug, but still small.  The straps made these shoes unwearable basically, it was like having your foot tied down.  So far I've worn these for two work days, and I didn't make it the full day either day.  I'm getting blisters and calluses in places I've never had either..  I'll keep trying to wear them in, but I'd be returning them if I hadn't already cut off the strap.  Definitely go a half size up at least..