I've been holding off upgrading my 2017 iMac 27" system for over a year now, due to fear of stuff breaking. But after seven major updates and numerous supplemental updates, I'm guessing that it's as fixed as it's going to be for the foreseeable future. And with macOS Big Sur around the corner, Apple's focus will shift to that, meaning that further updates to Catalina will be few and far between.
I'd already taken steps to migrate away from the 32-bit apps that were on my system, and the final hurdle was cleared yesterday when I confirmed that my old Canon PIXMA MP610 printer/scanner/copier would still function using Apple's drivers. So, after checking my system disk using Disk Utility, and making sure I had everything backed up, I went into System Preferences and hit the Upgrade button in Software Update.
As usual, the installation took its sweet time, so it's a good thing I had my iPad handy for reading!
First impressions on restarting and logging in were underwhelming — on the surface it doesn't look much different from Mojave. But then I started wading through all the requests for access to notifications, contacts, accessibility, full-disk access, etc. and I was reminded how much had changed under the hood.
Thankfully, since all the applications I rely on have had plenty of time to deal with the changes in Catalina, I've not had any unwelcome surprises yet. Some apps, like Keyboard Maestro, did require me to re-confirm permissions to control my Mac before they'd do their thing, and Audio Hijack needed pointing at the correct folder to store recordings, but after a few restarts everything is running smoothly.
I'm now going to wait and see what happens with Big Sur — at the moment, it doesn't look like all the apps I use are ready to work with it, and it sounds like there are still some rough edges to the new macOS.