This article is my opinion on the subject of html entities vs. png or icon files in a web application. If you have been watching bootstrap and seen the beta version of bootstrap 4 you might have seen some of the examples using entities. Initial I thought this was an improvement and in a lot of ways still do. But now I have given it some thought about the longer term of solution. I still think font-awesome is a much better choice to go because of the ability to modify the styles or simply create custom ones in a svg. I know entities are nothing new but just wanted to write out why I would use them in some cases and not others.
Use case for Entities
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Use for icons
Like I've stated I'm using font-awesome and in my opinion I think there are more scenarios that icons solve over entities. Now if only font-awesome was easier to modify in inkscape or a free tool then we're talking. You could do what you want with the icon files just as would with the sass files in font-awesome. Maybe font-awesome just needs a grunt/gulp package that looks at the sass files and adds/removes the svg related to css selector. Not that the icon files takes up a lot of space but it would make customizing it that much easier.