See my Fujifilm GFX wish list.
This example looks at image quality with the Fujifilm GF 110mm f/2 at late dusk, particularly very fine detail in wire and stone and roof tiles at distance.
Includes images up to full resolution from f/2 - f/8.
On an optical basis, I have no hesitation in giving my highest recommendation to the about $2800 Fujifilm GF 110mm f/2—this is the telephoto lens that anchors the system. For most usage the GF 110mm f/2 should be preferred to the GF 120mm f/4 for the extra two stops of light and the smaller/lighter form factor. Plus, so far the 110mm f/2 has shown itself to have much more accurate autofocus with only a trace of focus instability.