I tried to update from two developers that I have been using for years. Namely Tor and Hamrick Software. Apparently Catalina will only allow downloads from the App Store now. Also the desktop of Catalina Island will not work on automatic. I've also had several crashes. I had to revert back to Mojave after I was unable to update my software. That was the final straw.
Also, I know, this is a corporate decision, but I object to the Mac Pro 2012 being left out of the Catalina update when other 2012 models were left in. The 2012 Mac Pro is perfectly capable of running Catalina with certain graphics cards capable of running Metal.