07 - Cargo Management System

Anybody have any experience with the "Cargo Management System" in the New Body Style Sierra/Silverados?

I'm looking at buying a new Truck and I've narrowed it down to the Sierra, but I've got split feelings on this option. Main question I have is, are the rails removable (and how hard is it) if you wanted to haul something bigger/fragile?

I have a 2008 but do not have the cargo management system. There was a truck on the lot with one on it and I casually looked it over and decided I wanted nothing of that. There were aluminum rails mounted on the inside of the rails. I think it not made to come out but could be removed it would appear but would be lots of work.

My impression is this is for a contractor or someone who carries work tools etc.

BTW-It will only accept the system components that come from GM.