I have tried to write this post three times now, but hope that this angle will work.
Compromises.
What compromises can I live with, which ones can’t I.
Balance is the key.
The S5.
The S5 is the favourite at the moment, the “heart” choice. It is simply all of what I need, nothing of what I don’t.
I can live with all of its compromises, because of what it offers in codecs, recording formats, battery life (2.5 hrs), card needs (V30), ISO range (8000+) and DR (14 stop) performance as well as the added choices full frame offers;
The limited format and bit rate choices. What I want is there, in the form I want it and the benefit of the full frame sensor seems to allow it to perform big tasks with a small footprint. The cropped 4k 50p makes the kit lens longer/faster in length (30mm f3.5-90mm f5.6) and the very long recording time in 4k, 8-bit (or 1080p, 10-bit) is how I would roll, simply for practicality.
The AF is workable, but also not my only way of operating. It has hacks, alternatives (EM1x. G9, OSMO) and anyway manual is my preference. I will stick to Pana lenses and the ones that have a good rep (20-60, 50).
The different format and lens mount. Fact is, this is the secret of its success and adds another arrow to my quiver for stills and video. I could logically even go for a different brand, but the Panasonic quality and menu systems work for me. The future? No harm done either way. It may be a one hit wonder or the foundation of my future direction, but for the cost, it only needs to do a handful of paid jobs and I am square. M43 is my stills format, but video is open to what is needed.
The kit lens, which seems decent and the format is again the saviour. The slow aperture of the lens helps focus and retaining depth and it is video centric. Only $500 gets me a very good fast prime, but I may never need it and using legacy glass is an option. Back in the film era, medium format had better quality, even with a sub-par lens. In the modern era, full frame has become our new medium format, but the lenses are not a compromise, even the kit ones.
The small HDMI port. I can use a dongle, or not worry. I doubt I will use an off board recorder and if I do, I will simply be careful and build a good rig with cable protectors etc.
The GH6.
This is the “head” choice. It is the biggest, most expensive and by far the highest specification. I would never need the spec (6k, ProRes), or at least doubt I will and if I do, it will not be tomorrow. The S5 can be upgraded to this with a Ninja if needed.
I would happily use the GH6 for it’s merits, but this is something I cannot get past;
I cannot live with the card thing. I work with a redundancy, as any professional should and will not need the speed of the CFexpress only for backup. A $300+ card is too much for my work flow and I still have to address the card reader issue. An SSD would help and be cheaper, but then no power pack, so screwed either way.
The GH5.2.
This one will not go away, being the “gut” choice.
The only real issue is the lack of advancement the GH5.2 offers for nearly as much as the other options. It does however come without strings. It adds video options aplenty, just no DR or ISO mitigation and for the cost of only the kit lens more, the S5 does add these. I have several other good M43 video options, so adding a true video camera into this stable needs to add more than just a few more bloated codecs, VLOG-L (when the other two add VLOG) and unlimited recording. The G85 does most of that for half as much again. Still in the mix, but doubtful.