It never worked well for me. Not because it couldn't fetch ebooks, but because it defaults to adding an author's entire library, which was dumb for my reading habits.

I would search for a book, find it, only be able to add the author, and then have to uncheck almost all the books the author had written because I just wanted one.

Sorting by "books" just showed me a list of hundreds of books when I just wanted 7 of those.

If your workflow matched that for readarr, I'm sure it worked well, metadata problems aside.