I first bought the 10 m. They were too big. The 9 1/2's fit great with medium thick socks. A lot of room for the toes, which I need.
I usually wear a size 9 1/2 or 10 . These run on the big side of 9 1/2.  I plan to take these to Europe next month as my only shoes.
I usually wear my Keen Newport; these are just as comfortable!!!
Thanks Keen!

One note: The first pair I ordered, (size 10) were a little tight in the heal and pinched. The (9 1/2's) didn't do this at all. So each pair might be a little different at first. I think even the 10's would have softened in the heal after a few days if they had fit.