I'm currently using /e/os as there are no official custom Roms for my phone and they offer a GSI version (works on a wide variety of devices). For me it runs flawlessly, but I don't use any apps dependent on Google Play Services, so YMMV.
I think their default apps are very usable and having MicroG on board for location services is pretty handy. Their contacts/calendar/note syncing via Murena also make the user experience quite seemless.
I'd recommend it.
Edit: If you have any questions about the OS, feel free to ask away