I had a (custom) slider job done over the weekend by an outfit down in Portland. I will post pics when I can and report on their effectiveness after I've tested them.
Long story short, they boxed in the current LR Sidesteps (with steel plate) and bolstered the brackets some to effectively turn my running boards into sliders. ...also had to remove the fasteners and drill holes so that they could be fastened from the top for future removal. In the end, the sidesteps look exactly the same from 10 feet away. If you get closer you see screws (6) on the top and underneath it has smooth steel plating.
They may not be super-strong or able to take the weight of the entire vehicle, but for what I do when I go off-road, they will do the job. At the very least they will protect the doors. If they don't survive that then I can go with another solution after that since these were relatively inexpensive.