I like the idea of using an embedded font for icons, however I recently encountered some issues when I tried to make them responsive. With inline images you can easily use max-width:100% to get images to show at their proper size and decrease in size gradually while the browser window decreases in size. However with font icons this is quite tricky, you could use media queries to adjust the font-size but this is only useful for icons which are relatively small or the same size as text.
The icons I’m using are pretty big on a desktop screen, and shrink down to about 25-30% of their size in a mobile layout. I managed to get them to display well using http://fittextjs.com/ but I don’t think this is ideal, I’m concerned about memory usage on mobile and the authors themselves state it should only really be used for headlines.