I've been using Zotero as my "book" organizer. I have all my epubs, pdfs, everything there. Since version 7 I think you can read PDFs within Zotero, and I love it. I keep custom labels so I easily search for stuff. The only feature I don't use is everything about citation (funny enough). Before Zotero I had everything in file system directories, but I wanted the feeling of having one place (one app) where I could see all my books by category, by read/no-read, etc.
Having said this, I will probably wait a bit before upgrading to V8 (since I use it everyday, so I wouldn't like to face bugs and the like)
My experience with Zotero was similar - I tried adding my ebook library to it as an alternative to Calibre because I really want to sort of categorize and easily reference my books and/or get like library call number groupings which is not trivial with Calibre.
I deleted it after it only found about half of my books, which incidentially is my chief problem with Calibre.
Someday I will write an indexer with either a web search tool or an LLM interface to better find info on my books but for now I just spend too much time browsing through the files which makes me sad (but not sad enough yet to overcome the laziness)
> I deleted it after it only found about half of my books, which incidentially is my chief problem with Calibre.
Just find the citation on the web like at Open Library or somewhere, grab it, and add the book as an attachment.
I wouldn't drop it because all the stuff may not be done automatically. If you're going to read the books, you should be spending hours with them. I myself only put them into Zotero when I start reading them. I don't need to crowd it with wishful thinking. It's bloated and gets slower the more entries you add.
Having said this, I will probably wait a bit before upgrading to V8 (since I use it everyday, so I wouldn't like to face bugs and the like)