Well, I guess I have a differant viewpoint here. I use neither A. nor B. (spray or slip in) I bought my Ram as a work truck, and it is used for same. If it gets a scratch or chip inside the bed, who cares? Not me....it's MEANT to be used for workin', and such minor impeccadillos go with the territory.
It does not hurt the value of the rig at all, as such is expected to occur. If it's haulable, fits in the bed (somehow or other) then it is hauled. Rocks, gravel, sand, railroad ties, lumber, wire, or whatever has been and will be hauled in any truck I have without any additional 'fooferaws'!
The exterior/interior of the truck is well cared for, and most are surprised to find out that it is a '95', and now has right at a 100,000 on it...another 50,000 or so, and it will be time for another new one.
Oh yeah, I sold my 72 Chev lwb for 300 more than I paid for it new, with 165,000 on it, after 23 years of being used exactly as described above. Course I won't be able to do the same with RAM because it won't be as old, or be so 'collectable'.