Hm, I wonder which version is now included? STIX Two (now at V2.13) is regularly maintained, supports a bunch of opentype features and contains a very complete set of glyphs:
https://github.com/stipub/stixfonts/tree/master/docs — a well-made font indeed.
I wonder how it handles on an EInk screen, it originally was supposed to be a 'Times' compatible font, but Times has very extreme and thin serifs so I think they rounded STIX much more to make the it more suitable for digital use...