I am currently also a subscriber of Lloyd chambers blog and generally I appreciate his very critical view on cameras and lenses.
But - as a user of the GFX w/ 63 - I have to disagree with many of his critics because I just don't see them. Of course I only can speak for the GF 63f2.8 lens, because that's the only one I got (yet).
AF focus accuracy
If I select a small focus point and twenty times focus at open aperture to objects (w/ sufficient contrast) in various distances I 19 times perfectly catch sharpness at the focus area and 1 time I'm slightly off.
Of course focusing is not super quick because of contract detection but everyone knows that phase detection is technically impossible with this generation of Sony sensor, for that feature one has to wait for a camera update in 2018/2019 using the upcoming 100 MP BSI sensor.
Manual focusing
Of course it's focus-by-wire but IMO well implemented with very little clearance when focusing back and forth close to the perfect focus point.
It's true that somehow the image in the EVF or back screen does not 'pop' so much into the focus than other cameras (I will do a comparison w/ Sony A7RII) but I see no problem to focus correct manually, as I have to do using the Zeiss ZE 135f2, Leica R 180f3.4, Canon TSE 17, 24 a.s.o..
GF 63f2.8 performance
I would rate my Fuji 63 sample as one of the best lenses that I know and have, summing up all characteristics:
Sharpness
Center sharpness is perfect at any aperture (apart from diffraction closing more than f8 of course), corner sharpness is already impressively good at open aperture, very good at f4 and excellent at f5.6. My sample is also very evenly sharp at all four corners.
Focus shift
I did tests using a tripod, manually focused at open aperture at f2.8 to f11 at about 2 m and 3 m. Can't find any focus shift that would diminish image sharpness.
And: In autofocus, the lens focuses at the chosen working aperture (like Sony A7), so even if a certain amount of focus shift would be apparent, it would not cause any trouble.
Distortion
Fuji incorporated automatic correction for distortion, light fall off and chromatic aberration into the raw file (and the jpg, but I don't use). ACR carries out the corrections accordingly so one can't see them - normally .
Only if opened in Iridient X Transformer, switched off the auto-correction, exported as DNG and opened in ACR one can see the effects. Distortion is very little, maybe 1%, light fall-off at open aperture also, maybe half a f-stop, CA too. I see no problem in the auto-correction because I anyhow would apply it in ACR (apart from the fact that ACR adds a slight concentric wave pattern interpolation artifacts towards the image corners correcting the distortion, visible especially in darker even areas, but that's an Adobe fault, not Fuji's).
LCA
Very little greenish/ reddish halos back/ in front of focus point.
Bokeh
IMO absolutely great, one of the best I am aware of: soft transitions in the out-of-focus areas and absolutely round out-of-focus lights (at open aperture).
Otus comparison
Chambers every 20 lines of his blog writing repeats that the Otus (55) is better than the GF 63. The Zeiss Otus lens line is close to perfection, no question, but I don't see the point to compare again and again a manual focus 135 3K EUR lens with an auto focus medium format 1.5K EUR lens.
I anyhow would rate the resulting image quality of the GF 63 to be very close to the Otus (at comparable apertures).
I don't have an Otus but maybe I do a comparison to the (IMO also excellent) Sony/Zeiss FE 55f1.8 next weekend.
So far I'm perfectly happy with the camera and lens (just waiting for an one f-stop faster version ;-).