Hi chickenpoodle,
I haven't personally seen the insides of a non-JP bag in person so I am unable to comment about the wall divider. My first impression of the JP divider is that it feels like there is some moderate stiff foam like material inside there (just did a test squeeze).
oh!
i'm talking about the thin material dividing the two main compartments from each other. the thin material perpedicular to the one you just photographed.
sorry for the confusion!!