The issue with the factory liners is the limited warranty! It usually is only for as long as the truck has a warranty.
With LineX, LIFETIME warranty!!! Many dealers available also if you end up moving.
We have had a LineX for 2yrs now, no issues!
As for the step/ nerf bars, later tonight I will try to find the brand I had on our last truck. I think it was Ionic if I remember correctly! They were actuall blow molded plastic, so only the Al sub frame or steel brackets could have issues. Held up great for the 3yrs we had the truck. We had the black model, but also available in chrome. Only thing I would do different is have the steel brackets LineX'd to help protect them....
Only reason I didn't get them again is I still am having a hard time getting rid of the ridiculously expensive factory step bars our truck has from the factory! I would have never checked that option box!!! Lol