Rhino and Line-X are fairly evenly matched when properly applied. With a rubber based liner peeling is not usually an issue in metal that doesn't flex alot (beds, cabs) if the surface is scuffed evenly. As to fading, have you ever known of any product that retained it's color perfectly? It's a fact of nature that things fade, and black is the worst! There are products similar to tire shine that keep the liners conditioned quite well. And as far as coating the underside of a vehicle or using liners for sound deadening I have had nothing but good luck even with the cheaper Wal-Mart liners. The impact on road noise and heat transfer is well worth the time, not to mention the fact that is seals out rust. The one thing to remember is that if something is already rusty or unsound, adding a liner isn't going to help! Make sure it's prepped, and no matter how you go, it'll be better.
