With Poppler renderer its not as fast as MuPDF, but the Interface is also pure. For people who like it minimalistic, this is perfect as you have control via shortcuts and commands with ": -> Tab". If you have an up-to-date-distribution, you can build it on MuPDF-base instead of Poppler (https://github.com/pwmt/zathura-pdf-mupdf) to make it the fastest PDF-Reader in the world. With Linux Mint it has to be Version 20 (cooming soon), the actual 19.3 doesn't let you install MuPDF1.14 or higher, which is needed. For me, its simply the best PDF-Reader by far!
Its performance is like Xreader (really SLOW) and its interface is like MuPDF (nonexistent options, menus or customization). It's like the worst of both worlds. Avoid.
It surprises me deeply that this little gem have a negative score in the Mint Software Manager. It's by far the best OSS pdf reader I've stumpled upon.
It does take a few minutes to get used to controls. This, however, pays off quickly in fast opening and dealing with file and stable functionality across different distros. It's never the viewer of my first choice but somehow I always end up using it most.
Very light and fast, uses Vim bindings, so if you are a Vim fan, you might like it