When comparing SF Mono vs Hasklig, the Slant community recommends Hasklig for most people. In the question“What are the best programming fonts?” Hasklig is ranked 30th while SF Mono is ranked 32nd.
Ranked in these QuestionsQuestion Ranking
Pro Clear and dis·tin·guish·a·ble
Code is very readable at both big and small sizes.
Pro Best legible font
This font is legible in every condition.
Pro Beautiful with high pixel density
Pro Has a heavier appearance than Fira Code or Monoid.
Pro Great for Haskell
Pro Has many variants such as Italic, Bold Italic, Light, Semibold, etc., etc.
Pro Completely free and open source
Freely available via GitHub, therefore can be modified and improved by anyone
Con Apple is locking down this font
It's not open in any sense of the word. It even gives warnings if you try to rip it out of the Terminal.app or Xcode bundles. Obviously, Apple only wants it on their tools. This is such a shame. It should work in other editors, too. It's a beautiful font. Apple open sourced swift, why can't they be open with a monospace font?
Con Slightly difficult to use outside of Xcode, Terminal, or Console
The typeface isn't available in Font Book, etc. unless the user imports the files embedded in the apps above.
Con Lacks !=
Some coding fonts with ligatures, like Fira Code, turn != into ≠, but Hasklig does not. The reason for this is that Hasklig was designed for Haskell code, and so turns /= into ≠ instead.
Con No support for many editors, including emacs
Unfortunately, not supporting emacs is the number one reason I don't use this font all the time.
Con Very cute but not WYSIWYG
You want to see exactly what you've typed, not have your brain have to do a little dance every time you see one of these artifacts.