It really awesome when it comes to reading and annotating PDFs. That’s the main reason I got it — so many e-readers I’ve tried over the years have been horrible for PDF documents and as a professor that’s like 80% of my day. For ePub documents, it’s very capable now — even if that wasn’t the case a few software versions ago. That said, the experience is a bit idiosyncratic among e-reader devices. The Remarkable basically converts the ePub to a static document so that the UI can more or less treat it as a PDF, which is a different user experience than some other e-readers. It’s not unpleasant, but it’s different.