futtta on "[Plugin: Autoptimize] @font face"

Hmm, been looking at this and you might have discovered a small bug (indeed depending on browser).

If you're not scared of code, could you open up wp-content/plugins/autoptimize/classes/autoptimizeStyles.php and on line 449 replace

$replace[$hash] = 'url('.$newurl.')';

with

$replace[$hash] = 'url(\''.$newurl.'\')';

This should solve your @font-face and should hopefully not cause regressions.

Looking forward to your feedback,
frank