Can I ask what specifically you like about it over Photprism? Just the sync?
I've also been questing for a Google Photos replacement, and right now Nextcloud functions admirably for auto-sync but like garbage for anything past that like viewing albums afterwards. I've had an instance of Photoprism up for a while and was debating bringing it into "production" on my homelab.
The biggest one was that Photoprism doesn't have a mobile app. It seems a lot of people use PhotoSync (a third party app) to back up to a PhotoPrism instance, but I didn't even want to give it a shot considering they don't offer the premium features on Android. Immich on the other hand has apps that are developed together with the server and web UI, so everything is well-integrated.
I've also been questing for a Google Photos replacement, and right now Nextcloud functions admirably for auto-sync but like garbage for anything past that like viewing albums afterwards. I've had an instance of Photoprism up for a while and was debating bringing it into "production" on my homelab.