I made the change recently to Adobe's first open source type family, Source Sans Pro and as the exciting world of fonts goes, its been working nicely for me.
Fonts in code editors is something you tend not to think or care about too much, but when you are staring at a screen for hours it can help to invest a little bit of time. Below is a quick before (left) and after(right) ( from my BlogCFC2Html Node project). You can see instantly that its a more condensed font taking up less screen space but it also, IMHO, comes across as a lot cleaner right down to distinguising between a capital I and lower-case L.
