We do not know how fast that otherwise fantastic EVF in GH5 responds. That is an important point for action shooting. We do not know a whole lot in reallife about GH5 and actionshooting so advising people on the basis of very little information looks a lot like advising people based on a specsheet to me. I see no reason at all to advise any cam without proper reviews.
How fast does your G80 respond compared to the E-M1 II? It stands to reason that Panasonic's flagship won't respond slower than the G80.
I have a GH4. Respond to what?
Also, the claim to fame of the E-M1 II is the AF generally and continuous/tracking AF specifically. You've already stated that the E-M1 II is slower than the G80 and GH4 in low light, and I've seen one post from you stating that the E-M1 II is not as good in S-AF.
Not as fast in dark conditions. And surely not as good with the 20 mm 1.7 which in tself is already a slow focusser. But the thing with E-M1 to me is that even setting the right way to autofocus is a complicated matter. I have never useed the Gh4 booklet but soon found out how to use the touchscreen to set AF modi and AF points. Not so with Em1.2. I am not looking for the GH4 way, that is not it. Just calmly browsing throgh menu's and see what happens...It is not so easy.
I have changed some settings now and with the 20 mm 1.7 there is somehow not much difference. But in seriously low light with the 12-35 mm on it it is now very close to the GH4.
All in all: S-AF on the Oly is nothing to complain about. It is very solid, Panny is just the champ here. The difference in C-AF for someone who asks for its performance there seems more important don't you think?
That's enough for me to recommend the GH5 because you can be assured that the GH5 will match or exceed the G80 and GH4. Continuous/tracking AF are not everything. They're important, but low light AF is more important actually for most users.
It is very good on the EM1.2. Don't worry. It is like the Panny will get a fast focus in 19 out of 20 shots and Em1.2 in 17 out of 20. Something like that and if it is aquired it is every bit as fast. With the exclusion of the occasional lens.
And, again, if the G80 is right there with the E-M1 II continuous/tracking AF, I expect the GH5 to meet or, most likely, exceed that. This is something that Panasonic claims to have seriously upgraded on the GH5, which to me makes it likely to be the clear leader in all AF modes.
It remains to be seen if the G85 is right there with Em1.2. I don't think it is actually, the difference between current DFD and OSPDAF of Em1.2 is that the latter sticks to the subject in busy situations things moving in front. Current iterations of DFD do not do that. GH5 promisses advanced DFD and the difference from the specsheet seem impressive for sure. It samples 480 per second the DFD rather than the 6 times it does now. That is a HUGE difference. But how will it work? We'll see.
BTW: you have not addressed the EVF and the responsetime. That is very important too: how about the lag? We don't know.
Another thing is that Panasonic has been doing great AF with little recognition on MFT forums (i.e. Olympus forums) for quite some time, while Olympus has lagged considerably. I want to see Olympus be clearly on par for one generation before I actually recommend Olympus for this. You don't just catch up with one camera iteration. It takes time, and you have to go based on history when making recommendations.
Well their very first 4K video try is better than what my GH4 puts out. So there you go.
And I use em1.2 and the problem with this cam is surely not its capability, it is the best mFT cam out there now without a shred of a doubt including actions shooting.
Its main problem is (TO ME!) how much less intuitive it is compared to any Panasonic cam I have tried in the last 8 years.
After using the Em1.2 for three weeks, here is my short take on it when it comes to using it:
if you do not need some special features of an Olympus camera, do not buy one unless you are an engineer.
That is how I feel. I can come up with a load of stupid menu choices, the absurd situation of many knobs and not ONE that just lets uyou chose directly ISO etc with a turn of the wheel.
It is not made for photographers to my mind.
It is always indirect. You have this lever. Change it and now you can set ISO with the front wheel. But the next day there is a good chance you forgot to switch the lever back Now instead of changing shutterspeed you change ISO...Oh..set the lever back! Not big deal, but a constant deal. You need to remember.
GH4: dedicated ISO knob. It will always be there. Exposure compensation: it is on the body. Press it and change it. focussing modes: on the body, not with Olympus. You first need to hit one button, then you are in the menusystem and now you can change them...Isn't that great!
Why is a cam so snappy on one hand only to get in your way on the other because nothing is direct?
Yu want to select a multitude of failed pics which with 60 FPS can happen of course...
Now go to the touchscreen: and you cannot set the cam EVER to just point to every pic you want to delete. No. it will always need you to change that function from OFF to ON and then you can delete. Suppose one touch would mean immediate deletion we could udnerstand. But that is not the case: the cam will ask you if you want to continue and then you delete all the pics. If the cam is switched off, the setting is to OFF again.
It is counterproductive. It is typically how Olympus engineers think.
Set your cam on a tripod: swivle the screen out and shoot landscapes...Oooops: the sun comes in and you want to look through your EVF...Well: it won't switch to the EVF. It has such a capability but not when the screen is swivled out. WHY?
Is there anyone anywhere on this world that moves his eye to the EVF because he does not want to look through it??
The Panasonic is to my mind a cam that works intuitively. The Olympus cams, also my EPl5 is a cam that addresses your memory. Perosnally I can't see anyyone liking it.
The extra option in GH5 to create your own menuscreen could be another step up! I'll have to see how it works in reality, because Oly is also customisable like crazy but it is not straight forward at all. So wait and see.
If GH5 had a good HiRes mode and good reviews, I would probably sell my Em1.2 at a loss and go for that.
If video or video AF matter at all though, then the choice, again, is very, very clear.
Yes. GH5 will walk allover Em1.2 without a doubt. And any other cam in its pricerange btw.
SO why do I still have the Em1.2: because everything else about it is so good! The
Hires mode is splendid and works as advertised. The video IQ i s excellent too. The stabilsation is out of this world so good. The EVF is superresposnsive and stabilised for a very nice look! The video is supersteady!
The AF is excellent (but not in 4K video).
The still IQ especially in high ISO (colours) and lowest ISO is the best I have ever seen on a mFT cam. And we are talking RAW here and if you want subjective user reports: it really does seem that it is almost an ISO up over my GH4 subjectively. Biut not everything. Dynamic range somehow does seem on par, noise hmmm...may be just a bit better. But colours and tones seem a lot better at high ISO.
Low ISO: the shot for sure is visibly cleaner than on my GH4 at ISO 100 (which is already very good). What also helpsprobably is no AAF vs a cam with one and 20 MP.
The only downside that not constantly but occasionally bugs me is that darned interacing with the cam. Important, yes.
Conclusion: I like the output and functions in the Olympus but I do not like the experience that much while using it. May be it will change further over time and I have another opinion...Who knows.