They are better steps than they are sliders. The step is lower, making it actually more useful for that purpose than a body mounted step.
While they will most certainly slide over rocks, they occupy a physical space that is better left empty before the need to slide begins. And the leverage off of only the body mount also makes them weaker than a tub mounted slider that wraps the body. Meaning that if you land the weight of the Jeep on these, there is the possibility that they will bend up into the tub.
These are an aesthetically tougher looking version of a the common tube step nerf bar. And these are still steps that get in the way of the rocks.
What matters here is what you want from them and how well they will serve that purpose. Do you want steps that, despite getting in the way on occasion, actually work as a step? Or do you want a rock slider that doesn't get in the way until it needs to do it's job if protecting the body?