Wore this for a full day of rafting and barely noticed it was on, which says a lot for a life jacket. The thin-back design sits flush against my kayak seat instead of digging in, and the medium profile doesn't feel bulky when I'm paddling.
The ventilated back is nice on hot days, but the side straps loosen on their own after a couple hours of paddling. It fits fine and floats well, just wish the adjustment stayed put.