[frayed_knot]

I don't have either currently. I have a rubber mat. I have a tonneau cover too, I don't haul that much, but if I need to, I just roll back the cover and load up, the rubber mat protects the bed and keeps stuff from sliding all over the place. Have you looked into a bed blanket? They are pretty nice, looks like carpeting but designed to protect the bed. I don't know about moisture though.

All of my previous trucks had drop-in's. Never kept them long enough to worry about rust through, but they do scuff up the paint pretty bad. I never had the desire to take them out once installed, so I didn't really care about the paint. I think if you are in a salty environment, then a spray is the way to go.