Im using it for a couple of years. I flashed my fairphone 3 by my self back then, before the easy installer. It was the first time i did something “advanced” with a phone, but it worked quite well. After my fairphone 3 died, I bought a Fairphone 4 via murena. So everything was already installed etc In total I am happy with the Os. Their goal, the release of privacy oriented OS for everyone (so f.e. even my parents could use them) is quite of a utopia I suppose. But still, the team and community are doing a good job.
Yeah I already heard about grapheneOS, but its not working well with fairphone right? So murena it is for me :) And I would recommend to people, who are aware of the downsides and are little enthusiastic :)
It wasnt the battery, sadly. Some Fairphone3 have the issue, that their mainboard(?) is breaking down after a couple of years without any clear reason - and I was the lucky one. Its the only “unreplaceble” part and kind of phone breaker. Sure, you can replace this too, but it would somheow be like buying a new phone. At this point, the fairphone 4 was alreasy released, so I took the upgrade. Fairphone 4 and 5 have now a waranty of 5 instead of 2 years. So at least on this point ill be save for 3 years more :>