When comparing MT Andale Mono vs Operator Mono, the Slant community recommends MT Andale Mono for most people. In the question“What are the best programming fonts?” MT Andale Mono is ranked 32nd while Operator Mono is ranked 39th. The most important reason people chose MT Andale Mono is:
It's easy to distinguish "0" from "O", "a" from "o", and "I" from "l" from "1".
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Excellent legibility
It's easy to distinguish "0" from "O", "a" from "o", and "I" from "l" from "1".
Pro Good font variants
Boldface variant is not too heavy while italic face is not too spindly. Andale Mono contrasts with Source Code Pro, which is very similar in the regular font face.
Pro Has a script version
Operator can be used to mix the same font for syntax formatting.
Pro Super readable
Long strings can be read in Operator exceedingly easily. The font just flows nicely, with all the benefits of clarity that provides.
Pro Horizontal width not as wide as other fixed width fonts
You can legibly read everything and get more characters per line.
Pro Adorable italics
Cons
Con Not pure mono
Bold and italic are too wide, so it's not pure mono in combination with regular font.

Con Relatively expensive
At $179, this font is on the more expensive side.
Con Roman style isn’t very appealing
