I installed Catalina and with the exception of a ‘sign in to iCloud again’ issue, which I understand is quite common and was resolved with a call to Apple support, I have no problems - yet.
I don’t have any 32 bit applications as we’ve been told they wouldn’t continue to run on OSX for two (?) years. I was concerned about by Epson Scan with was 32bit, but that has been replaced by Epson Scan 2 which is 64bit. I tried it last night and it works fine, as does the Epson Perfection Photo V600.
I’ve played with the Sidecar feature which allows use of an iPad as a second monitor. I’m still working out how to easily get Lightroom to send an image to the iPad but I did manage to get a photo onto the iPad Pro and in develop mode was able to use the Apple Pencil to make edits and act like a Wacom Tablet (I’ve never used one, but the pencil and iPad seems to do the job I want it to). It appears pretty faultless, but it’s early days and any problems I’m having are probably user error.