throwing my .02 in as well.
I have had the fixed rear brace for a few years and am happy with it. I haven't found it to be that big of an issue with cargo space. However, that obviously depends on what you are hauling. What you can get it is also limited A. the rear cargo hatch opening or B. space behind the rear seats to squeeze by. I have found the cargo hatch to be the limiting factor more often.
I've still managed to fit everything from a mountain bike (front tire removed), a lawn mower, to sleeping in the rear with the seats laid down. (God bless Talladega 🦅)
(Mountain bike is just sorta angled in with the rear seats down, the lawn mower has the handle folded up but fits with rear seats up. If you go car camping don't forget the bar is there when you wake up and slam into it trying to sit up lol.)
That said, it is probably worth it for the removable but I've only had one or two instances of "aw hell, the brace is in the way." in the few years I have had it.