As for experiences: Used Inventaire a few years back, metadata was a nightmare, it was trying to pull data from Wikidata (nice in theory) but did not check if e.g. the author already existed, so there were five of them with varying degrees of data. No fun.
Bookwyrm is pretty cool, made the mistake to go to a small instance that was plagued by technical server problems, tried to export the books I had already put in and import it to a bigger instance, didn’t work (and was somehow not supposed to, I was later told 🤷♀️ Though that’s a feature that is apparently worked on). Other then that it’s petty nice, pulls data from Openlibrary, which works very well and you can also add metadata to OL if it’s not there. And the whole social thing with following people and writing reviews, good stuff.