I really like these shoes. They're my first pair of keens and def go with the advice to order a 1/2 size up. I float between a 7.5 and 8, and the 8 works perfectly. (even with a thin pair of socks--and i normally don't EVER condone socks with sandals, but for our flight these were my heaviest shoe and chicago was pretty chilly) black socks blended in fine. :)
BUT, functionally they're awesome. We spent 5 days in the Costa Rican rainforest and they held up beautifully, great arch support (i have way high arches), and if you tighten them enough you should be fine on any hike. Of course there really isn't the ankle support like a tennis shoe, but they were beyond comfortable to me. Add the fact that they are waterproof, and these were basically made for the rainforest. One of the hikes we did was down a waterfall/river (hopping from rock to rock) and half the time your feet are in the river. These were awesome, and way better than the tall boots the lodge provided that if you went too deep, you had a boot full of water the rest of the time + soaked socks. I agree with others that little rocks/sand get in there and is annoying to dislodge, but as long as you are near water they are easy enough to rinse out. Not a good enough reason for me not to get these.
Now that I'm home, I plan to wear these all next summer. They're comfy, simple to slip on, no toe stubbing risk, and won't slip off like flip flops can. Totally worth the money! (even though backcountry is not that expensive).
Also, I debated between these and the Newports and went w/ these mostly b/c there are less straps/coverage so more sun on the foot. :) I tried both on at local stores, and they fit basically the same. Thought these looked cooler, plus seems to be that a lot of people have the newports.