I'm giving it 5 stars. There was a piece broken during delivery, but was quickly replaced by Bak Industries. Great tonneau cover.
I've only had this installed a few days, but it's what I was looking for with the Rambox. Very low profile and easy to use. Had heavy rain a few days ago, and no leaks that I could see. Had it installed by someone who does a bunch of tonneau covers so can't speak to the installation, but the installer said it took him a little over 1.5 hours, the first one he did took about 3 hours.