I've tested font-awesome's circle-o-notch, yet the icon seems to spin asymmetrically, I've checked the CSS, nothing to indicate an issue
When inspected, it can be seen that the icon spins outside the zone the browser allocates, the parts that get out of the zone are truncated, therefore the icon looks glitched, as the edges get cut out
font-awesome 3's .icon-spin.icon-spinner doesn't suffer from this issue in the same setup
I've also tested using a custom icon spin class to spin the icomoon icons, yet the result is the same
Could the issue be related to icomoon's icon handling? / What's the best way to spin icomoon icons?