I have had the opportunities to examine all three and the good fortune of owning the G.
IMO, each of them has certain aspects that are better than the other two.
In terms of realism and color matching, R is top because patches of white ice cap are shown where they should be (at least until global warming makes them disappear), and the rose case complements the colors of the enamel dial very well.
In terms of gradations of colors (and if gradation equals artistic skills), G is best, as evidenced in the redish-brown in the areas of Europe and Russia and orange blended with yellow and green in North Africa . The artistry is just excellent.
In terms of attention grabbing, J captures eyeballs most quickly because of the contrast of the sharp yellow color in Africa against green which is mostly used in most other areas.
Although agonizing, I would place R and G equally on top.
Hope to see your P soon !
Cheers,
Gordon