Honestly, our truck has the bed liner spray-in stuff, and it's pretty nice (we bought the truck used and it had been done before we bought it). I don't think twice about dropping our heavy hitch on it, for example. It just makes the bed feel indestructible, and it has a plastic-like finish. Using it on the tongue seems like a good idea to me. I'm curious to hear from anyone who has done it.
I need to repaint ours, too. I said this last year, but... I plan to do it this spring.
1995 Airstream Classic 30' Excella 1000
2014 Ram 2500 Crew Cab with Cummins 6.7L Diesel
Sold but not forgotten: 1991 Airstream B190
Sold: 2006 F-250 6.0L Powerstroke Supercab