Frankly, I'm puzzled by your consideration of the G97. Don't get me wrong: It's a perfectly fine and competent camera, it can take some great looking images.
But the G97 (and G95 before it, which I own) has just a few standout strengths relative to the OM5ii:
- More controls and slightly better ergonomics/handling, especially with larger lenses. Not to say the OM5ii is bad — it is a superbly refined piece of kit with some subtle but nice improvements over its predecessors. It's simply that the G95/G97 is a slightly larger body, with slightly larger grip, which allows a bit better control spacing and better handling with the larger lenses in the system. There's also a rear control wheel (giving you three dials) which you may enjoy if you like shooting in manual mode, giving you dedicated wheels for SS, A, and ISO. This comes at a price for the G95/G97: It is a bulkier and heavier camera than the OM5ii.
- Far better quality 1080p video codec and unlimited video clip recording time. Lumix 1080p footage is absolutely remarkable for its level of detail and small file sizes, looking nearly as crisp and detailed as 4k footage from some other makers. The Olympus 1080p codecs on the other hand are ... dealbreaking levels of bad (if 1080p matters). On the other hand, 4k is decent (and you could always downsample to very good 1080p) and DCI 4k is excellent (but frame rates are limited and file sizes are massive).
- Slightly higher magnification EVF with a slightly larger eyecup. Resolution isn't any higher but probably a slightly better experience IMO for most people.
- Built-in flash. Might matter more now that the amazing Olympus FL3 flash doesn't work on the OM5ii for ... ? totally puzzling ? ... reasons.
Again, IQ for stills (RAW and JPEG) is mainly going to be a wash although your SOOC JPEG preferences may steer you towards one system or the other (O SOOC results tend to be the general crowd favorite but YMMV).
However, in almost every other way I can think of, the OM5ii is a more advanced camera in a smaller package (which many folks favor), assuming you're willing to step up to its higher price tag. Many action shooters also prefer the way Olympus allows you to save burst modes, AF settings, and so forth to custom presets on the mode dial; the same is not possible on the Lumix cameras since those are hard wired to physical dials and switches.
In particular, the OM5ii autofocus system will likely serve you better than the G97's which,
despite being far more capable than most people who've never used one seem to think*, won't can't quite match the PDAF of the OM5ii for the most difficult continuous AF shooting scenarios.
In the end, whether you
need what the OM5ii is capable of vs. whether you'd be satisfied enough with the G97 is nearly impossible to predict and varies depending on the individual, what you shoot, how often, your skill level, and your tolerance for misses.
FWIW I've shot Lumix for the past 7.5 years coming from Nikon DX before that across travel, wildlife (but NOT birds in flight which seems to be most people's point of reference for how unacceptable and terrible Lumix is), kids sports, etc. Sure, I've missed shots here and there, of course, but for the most part, I've been quite well served by Lumix DfD contrast based AF capabilities for my hobbyist stills and video needs. Its shortcomings, while real, I think generally aren't treated with appropriate nuance and get exaggerated.
One very mundane thing I'll mention is that if you've shot Canon 35 years, you may likely prefer Olympus zoom lenses over Panasonic lenses simply because you twist the same way as Canon lenses to zoom in or out. Panasonic goes the opposite (a la Nikon/Sony/Tamron). Some folks never notice or care. But as someone who grew up on Nikon myself, I can never, ever overcome the muscle memory and constantly twist my Olympus glass the wrong direction while using Panasonic zooms feel effortless. Not a problem for some on this sub, but it's a problem for me and enough others to bear mention.
Cheers.
--
"Gentlemen, it has been a privilege playing with you tonight." - Titanic musician before their final song
R The G100D is a low cost way of getting a feel for the basic IQ of a 20Mpix MFT sensor. The 12-32mm performs like a good kit lens and would give a false impression of a decent MFT lens. I’d get a used 12-35/1.8 mk i to experience a halfway decent lens or a used Panasonic Leica (not Lumix) 12-60. Panasonic OIS is decent.
