Comment by skydhash

The UI can be confusing at first. Bu take some time to get familiar with it and it can be really nice. The main benefits for me is dealing with poorly formatted epub and sensible viewing of pdf on small screen (kobo libra 2). There’s also OPDS support to connect to my calibre server instance and get book that way.

There’s no benefits if you get your books from the stores. But if you manage your ebook library yourself, koreader is great.