My vote is for Line-X. Have had mine since 7/01 and have had ZERO problems with mine.
Some minor nicks and gouges but nothing even close to going through. I have a couple of decent dents on the inside of my bed/wheel wells from dropping concrete/lumber/etc in there and the Line-X had actually flexed to contour to the dents instead of cracking or chipping. When it is first installed, have them spray it thick, my installer charged the same price.
My installer advised that any chips, nicks, dings gouges,regardless of cause, would be fixed for free by him as long as I own the truck ( which will be until it goes to the junk yard!) I can honestly say that the only spot on my truck with out rust, is under the Line-X. Its nice, fairly none slip(just enough slip to slide stuff in and out, but not to slide under way), easy clean up, fuel/chemical resistant etc.
I even Line-X'd the bottom of my Summit Climbing tree stand for huntin! Keeps my figgeted feet quiet while in the tree, LOL.
Only down side that I have seen so far was that the black has faded slightly over the years, before I got a tonuea cover, but Armorall would bring that back according to my installer.
Hope this helps.
J-
BTW I am in no way affiliated with Line-X, just satisfied customer.