the problem with spayed on bedliner on the body is that it isnt applied thick enough. but if it was sprayed thick enough, it would screw alot of stuff up (fit of panels, lights, stuff like that). i can hit my rhinoliner with linex all day with a pitchfork (yeee-haw!) and nothing will happen. If you got your rockers done thick enough, im sure it will hold up for a long time. its got a lifetime warantee, so why not?
just remember with whatever you use, if you incur any body damage and bend a panel it will crack off .. be sure you prep well and use something that is a little flexable to conform to the dent if it ever happens
just to sound like the hick i am :toothless ...i bought the cheap duplicolor from walmart in a gallon can and also bought spray cans for touch up...i was thinking i was going to clean my bed down to bare metal, that idea worked for about 5 mins then i got tired of paint dust sticking to me...so i just went over it real quick with a grinder and 30grit sandpaper on it....it adhered real well and the only time it comes off is where i carried some i beams in the bead for a week or so....i love the shit...spray it over rust even :beer
I use dupli colors black in large tall spray cans on my sliders and bumpers. Holds-up better than paint and is easy to touch-up. I got some roll on tinted to match my interior when I did it. Not as good as the thick spray ons (not spray cans). Be sure to ruff-up the surface for prep or it will pop off easy!