The xsporter is a solid rack system. I know two paddlers who got the racks caught on tree limbs or something. The rack didn't give and the truck bed rails took the damage. Solid.
They are also very easy to take off and remount if you need to do that.
Pricey, but well made. My only complaint was that the groove in the bars that accepted rack accessories used to whistle at highway speed. There is a little plastic strip that was supposed to go in there and kill the noise, but they'd blow off. Hopefully, Thule has improved that part of the system by now.
Recreational Kayak Paddle
Classic Freestanding Rack