The factory tube steps are just that, steps. Take them off if you are going to off road it. They won't help at all off road. I have the Shrockworks sliders and prefer the way they fit and they are relatively easy to install since they are bolt on. They are extremely strong.
As for a step, while that isn't their intended use they can accommodate. Not a lot of space between them and the body, so it's mostly a "toe" step. It gets me to the roof rack and my wife uses it to get in the truck.