I have installed Catalina on a late 2017 MBP with 16Gb RAM and 512GB SSD.
The install was straightforward and as expected 32bit based applications are now not able to used.
For a first beta the OS is remarkably stable.
Only issue I am experiencing is the desktop has become functionally useless.
This results in:
1. Click or second click functionality
2. No Desktop icons; no HD et al
Has anyone experienced this issue and if so do you have a temporary work around. Finder access to the desktop and associated drives and files is completely uneffected.