I’ve been using a Synology for quite some time, and I started using Synology Photos when it was first released. I’ve got somewhere around 85,000 photos in it now, and it’s been great.
Face recognition pales compared to Google’s, but I feel that’s to be expected given the slight difference in computational resources.
I back up my phone, my wife’s phones (work and home), and our DSLR photos. It works as expected and has been rock solid.
I’ve used it on a DS1019+ and now have it running on a DS1821+.
I’ve tried photoprism and while I was quite impressed, it wasn’t quite there for me.
My most important feature by far is automatic backup and I’ve had zero issues outside of having to reauthenticate occasionally.
As always, YMMV… But it’s been great for me.
And I’m another who self hosts Joplin. My wife and I use it on our desktops and mobile devices. We specifically switched to it from One Note and it’s been perfect for our use!
I used it extensively as I was writing (I’m an author) to make notes about things I needed to go back and correct, or an idea to incorporate, etc.