Ive got a Ranger Design aftermarket one in my current van and had a factory one in my old van.
Pros of the factory one:
Super quiet, you hear almost nothing in the back, looks very nice inside the cabin and of course its super stiff so there are no rattles on the panel at all
Cons:
Terrible, and I mean TERRIBLE seating position for tall people. My Ranger partition gives me so much more room behind my seat, I'm a tall guy so its all the way back and all the way down(if you have a SLT with the option). I had a serious problem with this before in my old van.
Pro's to the Ranger:
Cheaper, lighter, easy to modify i.e., screw things into.
Cons:
Noisy, vibrates at highway speeds, not totally sealed from the back so you do hear rattles and what not. Due to the nature of it having more space behind the seat it impedes into the door opening at the rear so its a tighter squeeze but nothing terrible.
Id look at some aftermarket ones, see if any of them have ribbing to cut down on panel flex. I know weather tech makes one, it might be similar in design to the Ranger.