(I'll preface this review by stating that I have several pairs of Keens and I love them all.  I have very wide feet with average/low arches.  Keen is the only brand I've found with a variety of shoes that fit well for me over the long term.)

I don't run, other than around with the kid and the dog, so I can't speak from a runner's viewpoint, but as an all-around lightweight comfortable athletic shoe, these are awesome.  They fit like a glove, I think due in some significant part to the lacing design.  Check out the pictures - instead of the laces being in a straight line they form more of an S-curve up the foot.

These shoes are really slim to the foot and the sole doesn't stick out past the sides of the foot which makes me feel at times as though I'm not wearing shoes at all.  The sole is very flexible.  I've found myself wearing these for hours after coming home without any urge to take my shoes off (we normally have outside/inside shoes, but with these I've been tending to forget.)

The one drawback I've experienced is that these shoes are so minimal, along the lines of barefoot shoes, that there is really no cushioning in the sole and as my feet aren't used to that yet the soles of my feet have been sore a couple of times at the end of the day.  This is after being on my feet and running around for a good 10-12 hours of the day, so no real surprise there.

I'm giving these 5 stars despite getting sore feet at the end of the day because I've understood from other people that my feet are probably adjusting.  I've had these for a couple of weeks now, and I'll try to remember to update this review after more time has passed.

I bought the solid black version because they were $30 less than the other colors and I didn't want to pay full price for this experiment.  If these shoes continue to work well I'd probably pay full price in the future.  All my other Keens have held up beautifully, some going on 5 years now, and these look to be equally well constructed.