If you use the PDF or e-book functionality in Edge, you may want to hold off on upgrading. The PDF scrolling is not as smooth as on the older version.
Zathura and Calibre are insanely bloated. FBreader is just no. Emacs works, but has similar functionality to FBreader.
As a matter of fact though, I think I have found a very good epub reader which I don't see mentioned very much called Cover.
It is ridiculously smooth at displaying epubs, maybe even more so than edge. I was reading an epub with tons of images and I could swipe left and right between pages multiple times without waiting a second for reflow, almost felt like swiping a pdf. Whereas on all those other apps the book was blurred and did not scale how I would expect it to, to fill the screen. On cover everything is displayed how I think it should be displayed without changing anything. So yeah, cover A+
https://www.microsoft.com/en-us/p/cover-comic-reader/9wzdncr...
I just checked the Microsoft App Store and Reader is available.
https://www.microsoft.com/store/productId/9WZDNCRFHWG5
Funny because with Windows Ink, I loved Edge's PDF abilities.
Made my life so much easier.
Not a deal breaker for me because I don't have a touch screen and use an external PDF reader (sumatraPDF), but if I was using edge for heavy PDFs I would be rather disappointed
Seems fine for PDFs that are a bit less extreme, but nowhere near as smooth as old edge.
Originally it was completely uncroped, and OCRing it seems to have grown it even larger.
Not too familiar with details with PDFs but I suspect it's just a huge DPI render (maybe designed to go towards being printed) that could probably be reduced significantly if it was designed for normal consumption.
All things considered it's amazing it works at all, but old Edge handled it a lot smoother.