I can second that, I've been using seafile and Baikal for about a year now coming from next cloud. The systems are so much smoother and less resource hungry. Next cloud is good when you have a small company, which I don't think applies to many self hosters. I have everything inside a docker compose setup, so everything from backups to updates is much easier, and with a nginx proxy and proper network isolation I don't have security concerns with running smaller tools such as Baikal on my machine.

That's just for files though. I'm looking for calendar and contact management as well

I'm playing with it now. So far so good, after a rocky setup.