I think it's time to elaborate a bit - so this post'll be on the lengthy side; sorry for that, but it may shed light on a couple of aspects I find quite important.
Let me start with stating that the M10 sure isn't for everyone - and that has nothing whatsoever to do with money. But for those who are like me and are into a certain way of creating images, I think there's no better camera on the whole market than the M10.
The reason why I'm so happy with the M10 is that it requires me to work consciously and deliberately and, whenever I do this, provides results that are enormously satisfying. Part of this has to do with the amazing quality of M mount lenses, but the camera is also polished and rewarding in use to a point I never had thought possible before. Everything just fits and comes together to form a package I couldn't be more pleased with.
In my personal case, it's important that the M10 brings enough to the table in terms of technology to be truely competitive - the M9, charming though it may be, doesn't provide a similarily modern sensor and processor. Fact is, files from the M10 look better and are better to work with than anything I can get from either of my two other FF cameras, the Nikon D750 and the A7 II. That's quite a feat - the D750's sensor is still one of the best 24MP sensors on the market, and Sony has built that sensor (the A7 II sports a close relative - but it's not quite that good, especially in low light).
This could mean the end of my quest for the right gear - and in many ways, it does. I've now travelled with a highly portable FF system of the highest quality - and it was just great!
However, the trouble is, the M10 will never be my only camera. For assignments, I often need tele lenses and AF because things are developing and I rarely get to control, let alone stage anything. That's why I prefer zooms in most cases as well.
Now, I tried lots of different systems and found that I really, really want FF files to work with (I actually deleted a long discription here - I hope it's for the better). However, up until last week, this left me with only two real choices: Nikon DSLRs and Sony A7 series cameras (I don't have anything against Canon, but I've been a Nikon shooter since the mid-80s, so it was just a question of consistency and compatibility with existing gear).
I was happy and impressed when the D750 became available; after much deliberation, I finally bought one. It is a nice enough camera in the hand, but most importantly, it is fast and reliable in use and produces very, very nice files, especially in low light. The D750 has been my event camera ever since.
But it does have two major drawbacks - the extend of one of which I only discovered quite recently.
The first one is obvious: A full system (the body with two zooms or three to four primes, maybe a flash, too) is big, bulky and pretty heavy, the rather "compact" body notwithstanding. This means that I can either have a reasonbly mobile setup or full coverage, and it's clear that I have to go for the latter when shooting events. Fun this ain't. But it's something I've been so far willing to put up with - because of those files ...
However, the second issue does bug me a lot more: As fast and seemingly reliable the phase detect AF system in the D750 presents itself, it turns out to have lots of trouble with producing tack-sharp images at the pixel level, specifically when using fast lenses. I do own such glass - most noteably, the Sigma Art primes, 24/35/50mm, and as a matter of fact, I see mush at the pixel level way too often. That's not because the lenses are duds - using LiveView reveals that they *can* be super-sharp on the D750. Yet, AF in LiveView on the D750 is sluggish and, IMO, unusable in any situation that isn't a studio still life setup. But why don't they work better in DSLR mode? Well, it all has to do with the fact that phase detect AF systems are the devil to micro-adjust and additionally are hard to keep fully fine-tuned. On the D750, the latter can - at least in theory - be achieved by using the "AF Fine Tune" function. But apart from being a crutch where there shouldn't be the need for one, this takes ages to set up for each lens individually, and moreover, the Sigma lenses usually need so much correction that you have to use their own USB dock and software instead of the in-camera system, which takes even longer and is even more tedious and frustrating. Still, I'd put up with this if it had to be done only once - but as a matter of fact, you have to re-adjust everything after some time, going through the whole unpleasantness again ...
My whole interest in playing around with manual focus on FF mirrorless - in this case, the only one available that fitted my needs at the time, the Sony A7 II - was triggered by this issue. Since diving head first into film photography, I had collected quite an interesting array of lenses, among them, most noteably, some renowned M mount glass that should at least be the equal of the - comparatively huge - Sigma primes. I wanted crisp images - so I was willing to do my share in getting them instead of relying on a flawed, however sophisticated, machine.
The Sony was - and still is - mostly fun to work with, but all told, if not used within its own eco-system of lenses, it's a poor substitute for a rangefinder or a SLR/DSLR. That's why I do like using the A7 II with the set of small, dedicated primes I ended up purchasing, but the thrill of shooting with adapted lenses wore of quickly. Not because of the results - but remember, I own and shoot quite a few film cameras, SLRs and rangefinders, and know what a good manual focus experience feels like. Even with a great piece of kit like the Voigtländer Close-up adapter, the Sony A7 II feels clunky and fiddly by comparison. On hindsight, I should have gone straight for the M10 that was fresh on the market at the time, but it's no use complaining about the fact that I tried not to spend too much money on a hunch alone ...
After all this, my next discovery came as a shock: Someone auctioned off their Commlite Pro adapter for little money - this allows the use of Nikon G/E lenses (with internal motors) on Sony mirrorless cameras with full AF (up to a point - the camera switches to on-sensor phase-detect ...). So I thought, why not? It would make the Sony into a adapt-all powerhouse if it worked in any usable fashion, so I got the adapter and tried it out. To my utter amazement, when I put those capricious Sigma Art primes on the Sony via the adapter, not only did the Sony A7 II acquire focus in about a third of the time the D750 needed in LiveView, but the images from those lenses finally showed their legendary performance wide open! The entry-level Sony with a third-party adapter of dubious quality (I haven't had any real issues with it, but others have) outperformes my workhorse!? Still, there's no denying it. I'll skip the expletive here - but you get the picture ...
What I want now is a camera with the AF speed of the D750 and the accuracy of the A7 II. It's possible that the freshly announced Nikon Z6 will provide that via the FTZ adapter. Then I'll have found my "other" camera - again, at considerable cost, but this'll finally allow me to get rid of a substantial subset of the digital gear I amassed over the last couple of years in the search of the perfect tool. Things look quite promising, actually.
In the meantime, nothing of all this takes away one bit from the joy of shooting with the M10. It's a different domain, really. One that's effectively untouched, untainted by all these troubles revolving around "the latest and greatest" - that's priceless, but it didn't come cheap. And it did take a whole odyssey on my part to finally get it - in every sense of the word.
M.