I'm a 9.5 M and these were my first pair of Keen's. I didn't know most people size up with Keen, so I first ordered my usual size. The experience was extremely painful. I got blisters everywhere, toes, both outer and inner side of the ball of the foot, even the bottom back of my heels. I later bought another pair of Keens in size 10 and realized that size was a better fit for me. So I ordered these again, in size 10. No blisters this time. One problem still remains though, the part of the ankle strap that's touching the inner side of my arches. I have low arches and my feet sit uncomfortably on this part of the strap and it's really painful. I hope it gets easier with time. I guess if you have high arches and get the right size, there should be no problems.
The toe box looks big (the smaller size looks cuter) so you have to like this particular look to enjoy them, which I do. I'm giving them a four because of the rough strap.