1. I did a comparison between the Fuji GFX 50s (with Fuji GF 63f2.8) and Sony A7RII (with Zony FE 55f1.8) using base iso raw test pics from imaging resource. I opened both in ACR and scaled them up to 200% directly in ACR (no sharpening applied). Look at the crops: The GFX upscaled pic is so much sharper than the A7RII pic. It's quite amazing what Fuji succeeded to squeeze out of the 44x33mm Sony sensor (and the 63mm lens is very sharp of course).
2. Enclosed a pic from today: GFX + GF 110f2 @ f2. Focused with small out-of-center focus point, the AF perfectly catched the boy's eye. The lens is tack sharp at open aperture and zero longitudinal aberation (the ear in the unsharp zone behind does not show any green color fringing). Few other lenses like Otus or the Art 135f1.8 or maybe also the Batis 135f2.8 are on that level, possibly quite no other medium format portrait lens.
2. Enclosed a pic from today: GFX + GF 110f2 @ f2. Focused with small out-of-center focus point, the AF perfectly catched the boy's eye. The lens is tack sharp at open aperture and zero longitudinal aberation (the ear in the unsharp zone behind does not show any green color fringing). Few other lenses like Otus or the Art 135f1.8 or maybe also the Batis 135f2.8 are on that level, possibly quite no other medium format portrait lens.