Is anyone noticing a speed loss with the later versions of macOS? I'm on Monterey 12.7 and have no need/desire to upgrade unless there is a significant performance increase or software necessity. I'm of the mindset that Apple will make older hardware slowly run slower with successive macOS upgrades, insuring the "need" to buy new hardware. That may seem conspiratorial, but... I also believe it's impossible to downgrade to an older version of macOS, once you've updated. Being that macOS is becoming more and more iOS-like and that's the way Apple does things for iOS devices, stands to reason macOS would suffer a similar one-way road...
It is possible to downgrade your M1 from Sonoma to Monterey. But it's a PITA. Here's the procedure:
https://forums.macrumors.com/thread...-silicon.2420265/?post=32972521#post-32972521
Alternately, if you have the space, you could test out Sonoma while keeping Monterey. To do that, create a completely separate partition (what Apple calls a "Container"), and install Sonoma on that. You'd probably only need ≈60 GB to install Sonoma and your most important apps. Then if you don't like it, you could delete the partition and continue to use Monterey.
Just make sure you have a full backup before creating a new Container--which you should have anyways.
I'd recommend creating a separate Container, rather than doing Apple's default, which is to create a new Volume on your existing Container. Having Sonoma on a separate Container ensures more isolation between Sonoma and Monterey.
Just two possible downsides:
1) If your work requires all your disks be encrypted, note that when the system creates an additional Container it will also create a separate small unencrypted, and unencryptable, partitition (don't know its purpose, but maybe its required to manage multiple OS's) that will cause your computer to fail the security check.
2) It's possible that installing Sonoma might create irreversible changes to your firmware. I've no idea if that's the case--someone with more expertise than me might be able to answer.