What with all the talk in here about roof racks and roof bags, has anyone used rooftop gear boxes? I have a heavy duty bag that I used to use, but dust, wind, UV and moisture have made it so yucky that I haven't been using it lately, as it's a pain in the ass to clean and it's heavy. I'm curious now about the Yakima Rocket Box or Thule Weekender or similar product. I would be using it on the factory rack. I don't have a proper roof rack and with projects piling up and money whittling down, it doesn't look like I'll be getting or making one soon. I can pick a roof box up used for a song, and it does seem tempting. I could use it to stow the light and bulky crap up and out of the dust. What have been your experiences? Are they worth it? Pros? Cons?