As a general comment and as a non professional, I only do small/ light lenses with the rangefinder, to me that's one of the main things that system's all about, making a grip out of the question. Bigger/heavier/ longer lenses whether native or adapted go on the Z6, a case of a big lens on one camera system not being so on another. This means missing out on a load of excellent RF lenses of course but I'm happy to pay that price.Just a little something about what I'd call the "Leica M experience", the less talked-about part of it. It's no secret that the M bodies can be somewhat unwieldy with longer/bigger/heavier lenses; in essence, the more front-heavy or "lens-heavy" the setup gets, the less pleasant it is to handle. Of course, while shooting, you will use both hands (it's manual focus most of the time - unless you use zone focusing, anyway), so it's general handling and carrying that's more of a problem. And it's definitely more of one for me personally because I really don't like half-cases and neck straps, so I basically have to carry the camera in the hand, using thumb rests/hooks or additional grips at best (and that's my decision, yes).
The M bodies are a dream to handle with small, light lenses. Here's what is bothering me: Three of my best lenses not only make the camera front-heavy but also cause the setup to tip forward when set down - and that's bad for the lenses and, possibly, even the lens mount, though I haven't had issues with the latter so far. The M 262, my older, bare-bones body, actually fares a little better: It's able to balance my best 50mm lens (for M mount), the Voigtländer APO Lanthar 50mm f/2, with no real issues. The same lens will tend to tip forward on the M10 (the camera I usually use it on), though it won't do it at all times, which makes things even more hazardous - and leads to me anticipating the worst and have the combo rest on the lens when on a flat surface. Not ideal. On both bodies, the Zeiss Distagon 35mm f/1.4 and the Voigtländer Nokton 50mm f/1.2 will make the whole setup tip forward. Both lenses already show some (minor) surface traces because of this, but I'm not really worried about that aspect - I fear the mechanics may suffer. Again, I can anticipate the issue and prevent accidents, but only be placing them in an unwanted position. What do do?
I do own a grip for the M10 (the original one sold by Leica - it's actually a whole bottom plate). And it actually solves the initial problem, at least for the lenses I mentioned above (bigger ones will still tip forward, but that's to be expected). However, unfortunately, the grip transforms the look and feel of the camera. I mounted it on the camera today for a walk through the capital of Switzerland and was less than impressed: With the grip, the M10 feels pretty big and clunky to me, and what's worse, the grip doesn't even feel deep and secure enough to have the camera dangle from my fingertips, something I do with most gripped cameras without worries. In short, yes, it's usable, and it helps with better balancing the camera, but mostly when it's not in use (see above).
Crucially though, for me, the angle between the fingers on the grip and my index finger becomes bigger and quite unnatural, and the grip feels more like an in-between, not really that helpful at all. The thumb hooks are at least as secure to hold, though admittedly, they don't help as much with balancing the lenses. But for me, it doesn't seem to be worth it to use the grip. I don't think it's badly made, but I'm questioning the concept: It's solid and pretty elegant, but just not big enough to be really useful. And furthermore, the angle thing I mentioned will only get worse the bigger the grip gets ... I now remember that I had a very similar problem with the additional grip for the GX9 - same thing, really, as far as hand positions and issues go.
So, all this means I have to put up with the tipping as well as the strain that can build up with heavier lenses when I carry the combo in the hand for longer periods of time, only using a thumb hook - though I have a couple of posture to help mitigate the latter, at least, but I still don't have a real solution for the balancing thing. I guess the only thing that'll help is even more care ...
Sorry for my ramblings about this ... I just wanted it to get off my chest, and maybe someone comes up with a neat solution; I'm resigned to put up with things as they are now.