I'm really disappointed in Catalina: I thought it would introduce better window-management features. The only new things are Sidecar and a few new applications / updated applications. For me, the only reason I would ever care to update to Catalina is if it's reported to be much faster than macOS Slo-jave. A massive performance decrease was offered with Slo-jave, so an update that changes things a bit under the hood is good enough for me. Otherwise, I'm not biting.