It's very messy, and labor intensive, but I am very pleased with the final results. It's a two day process to complete. But considering I was quoted almost $500 for a Rhino
liner, it's a great deal if you have the time.
Make sure to rub the paint down with xylene per instructions. It seems to soften the paint and make it bond with the Herculiner.
Important to take your time on the preparation. The little sanding pad they supply is not really abrasive enough, I found a similar 3m pad at the hardware store that cut the paint better, and also used my random orbital sander (used 220 grit), where I could lay it flat on the metal.
I haven't tried to drag an engine block across it, but I've carried some fairly heavy stuff around and have observed no chips or scratching.
They give you two rollers, one for each coat. Make sure to take the first roller off the handle right after the first coat; it's a pain to get off once it dries.
One kit (a gallon) does two complete coats on a short bed. You need more if you have a long bed.