I would be leary of how those mount to the vehicle. More than likely you pull out the body plugs on the back side of the rockers and they have an insert to put inside and they bolt to it. I myself am not keen on that personally because the rockers already have issues on these trucks rotting out, why have something attached to them and possibly speed up the process, or worse, fail and damage the rocker.
I know how cheap the aftermarket is on these things and it scares me... Hell even the tube steps I put onto my truck that mount to the body mounts, The bolts they give you to replace the factory bolts aren't even graded! The factory ones that are specifiied for the truck to hold the cab to the frame are grade 8. When I confronted the manufacturer they said no one had ever brought that to their attention, but nothing is wrong with it... Not only were the bolts not hardened they weren't coated to resist rust either. Decide to take the steps off, have fun with a broken body bolt in your cab.
Sorry for the rant, it just pisses me off that people think they know what they're talking about when they clearly don't.