Rated 5 out of 5 stars

Mozilla Firefox 10, 11 versions of forced underestimate the speed of data transmission. This can be seen in the screenshot http://www.speedtest.net/result/1822913913.png
Speed Upload - 11,49 Mb\s Very low
The old version of Firefox Setup 3.6.27 works well, without understating the speed, screenshot
Speed Upload - 70,13 Mb\s Very Good

This review is for a previous version of the add-on (1.2.1-signed).