Well, some may think I'm not objective, but I really am and I had both cameras before deciding on which one to keep. So with that said, my observations are based on my own experience doing A/Bs, Mark's A/Bs and some of the better GH4 videos I've seen (including Mark's UK footage). My comments are based on viewing all videos in 4K. There's little point for me to comment on 2K when I've got a 4K monitor. I might as well see these cameras at their best:
* Both my GH4 and Mark's do seem to suffer from those micro jitters. What's interesting in looking at Mark's UK footage is that there are a number of instances where it almost gives the appearance of autofocus micro misses. Mark did indicate he shot in MF mode, so it may be somewhat of the same effect I saw with mine (that odd effect with the 14-140 2nd gen lens), but to a much lesser degree.
* Both my GH4 and Mark's seem to hype the color (again this is a 4K observation and color can and does look different in 2K). I consistently dialed down my color to -2 and still felt many scenes were too oversaturated. I showed Mark's video to my wife and she agreed there were too many orangey complexions. Most of these seemed to occur in bright light. The best skin tones were in the shade or overcast skies.
* I find the AX100 AWB to be incredibly accurate. As I looked at my most recent Baltimore video, I find skin tones as well as other colors to look much more believable with none of the hyped greens I saw in my GH4 shots or others, including Mark's. Some of the grassy fields in the UK video looked much too green to me...almost as if shot with my Samsung Galaxy S5. I'm really not trying to be critical here, but rather just expressing what I've seen as objectively as I can.
* I still find, for the most part, the AX100's detail is unsurpassed. Although I would not describe Mark's video as 'soft' by any means, I see more detail in the AX100 videos.
So regarding Mark's A/B above (nicely done Mark!), these are again what I see in 4K:
* First clip- I see more detail in both the pink blossoms as well the bushes in the distance. Once again, greens look more convincing to me on the AX100. The GH4 rendition is just 'too green'. This smacks me in the face it's so obvious.
* Second clip- Virtually identical comments to the first. I just don't see greens that look 'that green' in real life. I had the same issues with my GH4. Again, looking at detail, there's clearly more on the AX100, no question.
* Third & Fourth clip- A bit harder to judge here with these close ups of the flower, but in a shot like this, I'd expect the 2 cameras to be closer. Differences in detail will be much more readily seen in wide shots, but I still see a bit more detail in the AX100.
* Fifth clip (shot of the needle plant...not sure what to call it)- I got a greater sense of depth from the AX100 shot as opposed to the GH4, perhaps because of the greater detail. Their rendition of green was different with the AX100 registering a green that looked closer to the color of those needles that I was accustomed to seeing around our old house. But again, it was the greater sense of depth on the AX100 that struck me.
* Sixth clip- Another shot of the needles- Again, a greater sense of depth to me with the AX100. The same difference in the color of green with the GH4 leaning more toward a yellower green.
* Seventh clip- Despite the shallower DOF in this shot of the purple flowers, I again felt a greater dimensionality to the AX100 clip, it was just sharper and more detailed. I thought color in this set was pretty close.
I know it's hard to convince some that I'm looking at these clips objectively, but I swear the AX100 always looks more detailed and I honestly feel the color is more accurate. These clips don't demonstrate skin tones where I think the disparity is even more obvious.
My feelings here just confirm why I decided to stick with the AX100. Don't get me wrong, if there were no AX100 I'd be delighted with the GH4, but I just feel the AX100 shoots a superior 4K image...with less hassle, no lens changing, no concerns over sensor dust, a better autofocus & WB. You do lose the ability to use specialized lenses, but for me this a very worthwhile tradeoff. My bottom line is always trying to get the best PQ regardless.
Again Mark, nice job on these A/Bs.
Edit: One other note, the zoom range. I find having that 10-15X zoom lens (depending on which IS you use, Active or Standard) on the AX100 to be another tremendous asset. I can't do that with the GH4 unless I carry a large lens for that specific purpose.
For me, when on a long trip, lighter is better and the AX100 offers a more complete package with no need for other lenses.