I was also convinced to install it, although after trying it, it looks more like less for PDFs than vim for PDFs (as many of the commands search or scroll in complex ways, but none of them modify the PDF).
Still, it's interesting to have something like less for PDFs!
Zathura can use mupdf as its PDF renderer (it can also use poppler). I like using the mupdf library through Zathura rather than using the mupdf application, because Zathura has plugins for other file formats too, like PostScript and DJVU, and that way I learn a single set of keystrokes to view all sorts of documents.
Still, it's interesting to have something like less for PDFs!