Met up with a Feeder Driver from Phoenix who has one. He loves it. Takes seconds to set up.
Lots of our guys use hammocks but not that expensive lounger. Most any cheap hammock will do, I prefer a net kind for air flow.
The cab is designed to hold the weight of the entire tractor with the doors closed (set upside down, not with variable accident forces according to a former automotive engineering friend of mine), so these won't damage the doors. Opening and closing, pulling on the door as you climb up does more damage over time. The Kenworths and Freightliners doors seal much tighter than the Macks ever did. New Freightliners will sound the horn if you don't shut the door with the window cracked so it seals tight.
A well rested Feeder driver is the safest Feeder driver.