This release improves the script performance by about 28%. On a 190KB CSS this means it saves over 4secs exectution time. This is likely to help users facing #22, unresponsive script in Firefox.
The polyfill still has some big performance issues when applied to many images or when a big CSS is on the site but this speeds it up a lot.
Comparison: ![before: took 18secs to complete script executio...