I really wonder what about this edition is "improved" over the original. It looks pretty much exactly like it, and also has the 640y480 limit. But the worst thing is, the text is almost completely unreadable. The pseudo-antialiasing makes letters and letter parts blend together. Did I miss an option, or is it supposed to be like that? Are there "fan fixes" that at least make the text readable?

Do you mean Real Myst ME, or Myst ME?

Myst: Masterpiece Edition. realMyst: ME is fine (lack of any translations aside).

I haven't played in a few years, but I don't remember issues with the text. Maybe it's a ScummVM thing?

Unlike RealMyst vs RealMyst: Masterpiece Edition, the differences between Myst and Myst: Masterpiece Edition are just about image and sound quality. The first release of Myst had 8-bit color renders of Cyan's images and lower quality audio effects. Same game and assets, just not downsampled like the original was for the hardware it was targeting.