They run great, I wouldn't use them for long sprints like I would my Merrell Chameleons. If I had to compare 'em these would be like if you cross-bred a Chameleon with a Sawtooth and then made the build quality even better while dropping the price by half. But frankly they're great boots, hands down.
Support is great for being a mid-height boot, break in took about a week before they became comfortable enough for me to want to really use them out in the field (I ran these in the Magpul Carbine 1 class and they worked perfectly).
It also doesn't hurt that I can actually see Keen's office from where I work. I'm only 5 blocks from their office. And I popped in to thank 'em, great folks.