Thought I would add my experience in both fitting and using the Chief rear bar on my GC Trailhawk.
Fitting took about 2hrs, I was pretty careful with the rear bumper removal and setting out all pieces to make the install easier. It can be a little fiddly in some areas with the side wing mounts but the only real difficulty I had was the main centre frame which appears to be off by a few mm. After some pushing and prodding it was actually pretty easy when I used the jack to lift the main frame of the bar and use the vehicles weight to push down and lock it in for the bolts to line up. The end result despite this difficulty was a bar that won't rattle so I'm pretty happy with it.
In terms of actual use it has already saved me some damage. I spent a week in the west coast of Tasmania and encountered numerous rock ledges and ruts. It took a few whacks which has scuffed the paint on the bar but no damage at all to the car bodywork. The only think which I did find was that through mud the bar actually scrapes up mud and traps it between the bumper and bar and also the exhaust, you can see this in the photo attached. Not sure how you could fix this in the design but it wasn't a big drama, the mud came out pretty easily with a high pressure hose.