Sample page Rated 5 out of 5 stars

http://io9.com/5929783/jetpacks-voldemort-mary-poppins-the-most-ridiculous-fantasy+fueled-images-from-the-olympic-ceremony

I stand on its pages a few minutes and then I close all tabs. But the processor is busy on 40-50% until the browser is closed.

This review is for a previous version of the add-on (1.0.6).  This user has a previous review of this add-on.

Thank you for the link. We will investigate this issue.

EDIT: We have just released v1.1.1 which reduces the CPU usage by this extension and improves the user experience.