4 liters between two different brands mean nothing, as often brands have different means to measure the volume. Most use the number given by the computer-shaping software, but actual volume will vary with the post-shape and glassing. (and the Deep is listed at 126 liters, too, BTW)

The shape is much more important.
They seem quite close. From the pics, the Deep seem to have a slightly wider nose, that will bring a better stability. But the most critical parameters, rocker and rails are not listed nor visible...

I have never seen any of them in real life, nor ridden them, but I would go with the australian build rather than the asian production. Gong is now re-localizing its production from China to Portugal, and can now compare the same board shapes with the same specs build in both factories: the european one is lighter ( ~ 1.5 lbs on a 7'6"), and nearly 4x more impact-resistant. This is due to the quality of workmanship, tools (the CNC) & materials (resin, cloth, and especially the blanks).
Plus Jackson was riding for JP, so the Deep model seem an evolution of the JP shape.