At the moment I am not upgrading because I regularly use Aperture for photo editing, and it will be unusable after the update. I bought it 5 years ago, and it's worked perfectly since then, meeting all my needs for photo editing and not even feeling remotely dated in terms of UX/UI even with all the OS updates since then. I have no idea what I'm going to replace it with, since I really don't want to go to Lightroom and it's subscription model.
If you are looking to replace the 32-bit-only Aperture with something else for photo editing on Catalina and don’t like Adobe’s subscription model, you may want to consider Capture One. It is actively supported, has the “buy and own” option, and is very capable though its interface may take some getting used to and/or customizing.
I tried the demo earlier this year and liked it a lot, and they even happened to have a promotional discount at the time, but for whatever reason the purchase button was broken for me. I’m sure it was either just my machine, or Phase One has fixed the bug long ago.
