Shoes fit perfectly. Very comfortable with good support and toe room. I like the removable insole, as I have plantar fascitis, I remove merrell's insole and replace it with superfeet insole. This is a shoe that I can wear all day, without the sore feet at night.
Yes, this shoe does run narrow- I have a narrow foot and it is my favorite thing about the shoe. I find the shoes to be hot and un-breathable, to the point that I'll only wear them in cool weather. They also don't have very good arch support, so I wouldn't wear them to walk much further than a block or two. The mesh nylon grids on the fabric tend to collect dirt, so they are harder to keep clean (but no leather, so they are washable). I take these traveling with me since they are light to pack- I wear them basically as a slipper that can also function as a backup pair of shoes in case my main shoes get wet.