I bought a pair of KEEN sandals back in May or June. Never heard of the brand before, but they looked to be quality. I actually considered posting here for brand feedback myself. Apparently they are a British brand.
Ones I bought are basically
these except they have "BISON" brown leather uppers instead of canvas. They were $80 at a local shoe store, way too much to spend on an unknown brand IMO, but I was desperate. They are definitely worth the $50 REI is asking.
I've been wearing them frequently this summer. They are comfortable, a perfect fit, and have a smooth leather(?) top sole (or insole, whatever it's called), that does limit odor. They are holding up just fine after a couple months of wear and a bit of creek-bed walking.
I give them a :thumbsup: based on my experience so far. They'd better be durable enough to justify the $80 I spent.