When comparing Envy Code R vs Liberation Mono, the Slant community recommends Liberation Mono for most people. In the question“What are the best programming fonts?” Liberation Mono is ranked 17th while Envy Code R is ranked 23rd. The most important reason people chose Liberation Mono is:
Liberation Mono works well with hinting on high-resolution displays.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Clashing characters are easily distinguishable
This font offers very distinct programming characters that help differentiate the following clashing pairs: {} vs. (), "0" vs. "O", and "1" vs. "l".
Pro Easy on user's eyes
Envy Code R is quite narrow (like Anonymous Pro) but at the same time squarish. The letters are easy to read and offer a pleasant reading experience.
Pro Fills out the space well
Envy Code R also fits more into a given width when compared to Source Code Pro.
Pro Bold font is the same width as the regular weight font
The bold version has the same width as the normal version which is useful for syntax highlighting.
Pro Very readable
Liberation Mono works well with hinting on high-resolution displays.
Pro As of 2023: Second Best screen-modern drop-in replacement for MT Courier New
Metric-compatible with Monotype Courier New, dot 0 (zero), modern non-Kettler lowercase l (ell), 660+ glyphs, OFL-1.1 license
Pro Compact line height
Just like Courier New (the metrics of which this font emulates), its line height isn't too big, which results in more lines on the screen, compared to Consolas and several other more popular fonts.

Pro Has Bold typeface
Cons
Con No Cyrillic glyphs
There are no Cyrillic glyphs in Envy Code R which may be an issue for Russian users.

Con Lowercase "w" is distracting
The lowercase "w" is a bit distinct looking due to the narrow nature of the font. This could cause a distraction to some users.
Con Difference between "0" and "O" isn't clear
It can be difficult to tell the difference between the number "0" and the letter "O". However, the Fedora Project has a slightly altered version of Liberation Mono that fixes this with a dotted zero.
Con Liberation fonts are ugly
