The website lists an install time of 40 minutes. I figure they're off by a factor of six. Maybe if you're in a fully-equipped garage with a hydraulic hoist and an experienced crew you could do it in 40 minutes, but a single decently-equipped marmot doing it for the first time... well, I was out there for over three hours, and I still need to run a power wire from the battery to the tailgate to power the wiring package, which is probably another 20-30 minutes.
Bear in mind that I'm also doing a careful install job, siliconing the nuts as I'm putting them on to help prevent rust and loosening, doing touch up paint on the bits that were nicked in shipping and so on.
Gonna change up clothes and go for a little drive to make sure that everything works.