I've never had any issues cleaning my truck bed with a pressure washer, and I don't think it has faded much at all (for 17 year old Line-X). Sure, it doesn't look shiny & new like the above photo, but I also don't apply any tire-shine or other product either.As someone that has owned a Line-X or Rhino-lined truck beds for over 20 years, I can assure you they do not clean up easily. They also fade.
I live in a red clay state and it migrates into all the nooks and crannies of the texturing and it becomes impossible to get out. Both types do a good job at protecting the metal underneath (Line-X more so because it is harder) but I would NEVER put it on an outer panel that I was trying to keep looking clean. It's also heavy...
And to chime in on the original topic...my favorite is a painted top and fenders but I really fear the rock chips- especially the rear fenders.