I'm planning to switch from ownCloud to Nextcloud in the next weeks. Does anyone have experience with that or maybe some advice? Aside from creating Backups.

Nextcloud has instructions on how to migrate on their site:
https://nextcloud.com/migration/

I never tried it but it seems quite easy

I'm not really an expert but I set up my Nextcloud 2 months ago and it still works fine, so it seems I did something right.

Just don't forget to assign users and folders in the web interface after installation. Took me 15 minutes to figure out why the hell it didn't sync lol.

I have thought about moving to nextcloud from owncloud, but I have problems taking backup of 6TB data and 30 accounts lol

@Zennoe
Friends, family, People that need a temp storage

@Linux
Never tried nextcloud, but since it's a fork, you can probably point the data folder to the old one, and run occ equivalent to scan the files after you imported the users.