Sumatra PDF is a PDF, ePub, MOBI, CHM, XPS, DjVu, CBZ, CBR reader for Windows

Text rendering in Sumatra vs Acrobat

Sumatra is on the left, Acrobat is on the right. Text appears much clearer in Acrobat.

Desktop resolution is 2560x1440. Both programs running in full screen view.

Any way to get better text rendering in Sumatra? Or is Acrobat my only option?

White lettering on dark is not your average text and in many cases SumatraPDF can appear better since it does not attempt enhancing the MuPDF Anti-Aliasing any more than the default.

You could try raw MuPDF-GL which can toggle Anti-Aliasing on and off and has some other colour related settings but for reading that White on Grey perhaps stick with Acrobat.