I have been using Own/Nextcloud for about 4-5 years, initially as a replacement for Dropbox/Google Drive for file storage, calendar and contact synch.
I originally installed it on my homeserver and have had it running there since. I use it continually, every day. I’ve followed a really good install documentation from a guy called Carsten Rieger (https://www.c-rieger.de/category/nextcloud/). They have good advice on hardening the install and so far I’ve not had issues.
Since they’ve started releasing more apps, I’ve started using it for as much “cloud services” as possible to remove my reliance on other cloud services as possible.
I’ve not got it installed via YNH, but I have been thinking about it - the main thing holding me back is, I use it for work and if it goes down it’s a big annoyance. I’ve only been using YNH a few months and don’t have enough troubleshooting skill yet to fix it quickly enough.
Right now, I’m using it for file storage, synching photos from/to my devices, web-mail interface (Mail), bookmarks (an app called Tasks) (daily things, FOSS projects, work, etc), tasks/todo (Tasks), rss reader (Nextcloud News), tracking my location (Phonetrack), web-conferencing (Nexcloud Talk), and web-radio (Radio).
I did have Collabora Online working once but then an update broke. I want to get it working again.
For backup I have my data on an external disk, it’s rsynched to another disk and the NC configs are backedup to the USB disk also. I also have everything synched to another desktop machine.
My ideal situation is to get YNH installed on a second home-server, with all the apps I use via YNH, also install Collabora or Only Office, and then connect that to my stand-alone Nextcloud.
I really recommend people try Nextcloud as an alternative to commercial options.
I hope that’s useful to you!