I coated by metal bumpers in it.
it chips off pretty easily
the better prepared the metal is underneath the better it holds up (scuffed up and CLEAN before you apply)
The reason I used this stuff is because it looks and feels better then flat black paint and because I can easily hit my bumper with a wire wheel on the end of a drill, clean up around the chipped area, clean the metal and re-apply.
I use the spray cans..... I re-do my bumpers about once every summer to keep the rust away and them looking nice.
Doing your whole truck is a good idea, as long as you prep the paint underneath you shouldnt have a gbig issue, and like stated, if it chips, just scratch the chipped area to remove the loose stuff and re-spray.
I am planning to use a product called Bull Dog bed liner, I will roll it on.
I am using bull dog because its super tough and available in any color.