I thought it would be useful to post an update on how my M1 is going after a month's use.
In general, it is indeed a very nice machine, and despite anything noted below I am not at all sorry to have bought it sight unseen (ordered the day after launch).
Whether it is worth the cost for someone with a newer original machine (e.g. a 2020 MacBook) I cannot say; the additional performance is noticeable, but it would depend on you use patterns.
The one area I have struggled with a lot is the migration of applications from my old machine. Obviously, they were all Intel apps, and although many work seamlessly with Rosetta 2, some have not. VirtualBox is one, which I was using with vagrant for development work. The MacOS migration dutifully ported the app over to M1, and installed it in so far as that is possible, but various low-level parts cannot run under Rosetta and so, even without running VirtualBox directly, there were background problems and failures. In the end I downloaded the install package to get access to the VirtualBox uninstaller, which duly wiped everything related and all was well again.
The worst problem was with the Adobe Creative Cloud apps, which were ported and appeared to start up ok, then failed completely despite using the CC updater to update to latest versions. Again, the only fix was to completely wipe all CC apps from the system using the downloadable Adobe CC clean uninstaller tool, reboot, and then reinstall from scratch. Lesser options didn't work, I presume because something in the common support files was broken.
Other similar issues cropped up with the Wacom and Logitech USB control apps as well, which also needed to be wiped and reinstalled fresh.
It seems to me that the right approach for Apple with this would be for the migration assistant to include a list of apps to ignore when migrating, which would include apps like VB (which plain cannot work on M1) and Adobe CC (which seem to have problems). Being told it is necessary to reinstall is a lot less of a problem than trying to debug apps breaking in strange ways.
I have come to the conclusion that I preferred the sloping case styling of the 2014 model to this one. This model's case is blockier, slightly heavier and in my view not quite so "swish". I will (have to) live with it, but this style would not be my choice.
In my earlier post I mentioned various aspects of the hardware, including not particularly wanting the larger touchpad. I am still of that opinion -- the larger area just means I have much less space to rest my hands between thoughts, and so tend to tap the pad without meaning to. I haven't yet discovered a case when the larger pad is an advantage. In my mind it's just "larger for the sake of it".
Much has been made of the return of MagSafe, and I agree it is a benefit and much prefer it over USB-C alternatives. However, I have found that the "plug" drops out of the socket much more easily than for the MagSafe 2 version on my 2014 Mac. I presume this is partly because the old version had more of a slot to go into than the new one. I don't think it's because the magnet is weaker, although that would be the initial assumption.
The new keyboard may well be better than that used on some recent MacBooks, but again I still prefer the 2014 version. I guess I will get used to it (I'm already decently fast on it) but there was something about the feel of the keypress on the older version that felt right, for me. I have also noticed that using the arrow keys (bottom right) isn't quite as easy as it used to be, though I haven't worked out why.
Good things include the fingerprint sensor (one of the reasons I actively wanted to upgrade), which has been as useful as I hoped it would be. The only thing I could wish for is for a fingerprint press while at a password prompt in iTerm2 to cause my system password to be inserted :-)
Battery life has been a very mixed bag. In some cases, it's been astounding: 2 hours of watching a film on Disney Plus via Firefox dropped just 10% of battery. Conversely, sometimes a couple of hours of gentle writing has dropped 40%. I feel there is room for optimisation of some background tasks, and one candidate I've noticed in Activity Monitor has been "mds_store", the Spotlight file indexer, which has sometimes been at 150% CPU (i.e. 2 CPUs at ~75% each) for hours at a time. For the moment I have basically disabled Spotlight and we're back to no energy-hungry background processes. This doesn't feel like the right solution(!), and there may be a link to the Migration woes.
I have mentioned some software niggles elsewhere, but I do have to say that in the main Apple have done an amazing job of ensuring that most apps "just work" with Rosetta 2, and do so without noticeable performance penalty. It is an amazing achievement, and I can say that as someone who has previously developed software with similar goals. I do hope that once the need for Rosetta 2 within MacOS passes that Apple release it for other uses in some form.
I am not wonderfully enamoured with the changes in MacOS Monterey; some are nice, but some look, to my mind, change for change's sake. I'm thinking particularly about the updated graphical style of notifications, which in one way is nice, but it's also out of keeping with other parts of the UI.
The continuing move towards locking down various permissions is, in its way, a good thing, but I feel the UI for managing it and modifying those permissions needs a lot of work: it is too hard to navigate and understand the implications of choices. Even Android does that part better!
Much was made early on about the Camera display "notch", but I cannot say it has really bothered me, though I would rather not have a notch at all. The main time I notice it is when an app with more menus than usual causes the menu to skip to the right hand side, which looks odd.
To close, then, the M1 MacBook Pro is a lovely machine which is sadly slightly marred by some glitches in the software (especially Migration, Display control) and the hardware (trackpad, mainly, but the feel of the keyboard too). I have had very little