I use /e/OS on my OP7.

• Their tracker/ad blocker is great.
• Their app store has a rating about privacy/tracker for each apps.
• They implemented tor in the OS, and you can choose if you want to activate it and for which application.
• They have a mock location feature.
• I get monthly update, and it works smoothly.
• You do not need to use murena account to use the OS

For the drawbacks :

• They have an app store that can install both applications from the play store and from Fdroid, but it isn't very convenient as you can't add Fdroid repos, nor uninstall applications with it. (and I'm unable to use it to install applications from the play store for more than a month, I've installed the aurora store )
• Most of their system applications are open sources applications available from Fdroid but with a different icon and name.
• Their navigation application named "Maps" is a rebrand of magic earth.

It's all I have in mind at this moment.

When I'll change for a fairphone, before turning to /e/OS, I'll probably try iodé OS. It seems they have similar privacy /anti-ad features but the OS might be less bloated and the system app are not rebranded, they keep their original name and icons.