I did my sliders and both my slimline bumpers. I like the line-x stuff I have shmucked into an oak tree and slid it along rocks and whailed on the the bumper with a sledge and nothing. But dirt and tree bark that do get ground into the the texture take a bit to get out (so I don't bother to do it)
I am happy with the line-x and it is warrented for life, so if it peels around recovery points they will re-spray it. The only thing I would suggest is to spend the 50-75 bucks and sand blast it for the best results.
Ross T