A lot of people complain about issues, but a lot of people think they're smarter than they are. So YMMV. I had no issues at all with any of the Macs I've installed it on.
There are a lot of small things I found that I really like about Catalina, but some of the larger things I like:
- Podcasts app
- Updated Notes & Reminders apps are cool!
- AppleTV+
- Improved stability when connected to servers (particularly Windows-based servers)
- Improved speed and stability with Safari
- Finder integration with iPhone/iPad is slick!