See my Fujifilm GFX wish list.
This is an in-depth evaluation of the 63/2.8 with findings I consider highly relevant to the GFX system. I consider this distance scene as one comparable in makeup as to what one might do for a landscape shot (wide range of near to far detail). It has a lot of very fine detail at distance for checking out performance.
Includes images from f/4 to f/16 at up to full resolution along with large crops.