Rated 5 out of 5 stars

The bar graph in the add-ons bar is exactly what I wanted to show me when my system is using too much memory. I have other tools that show me network up and down and what Firefox is using so this is exactly right.
The only slight complaint is that the colours for the background and foreground are not rendered properly in the bar graph. The only one I could find that looked really natural was purple for the foreground. That works well as the increased or decreased memory is traced with a lighter colour across the top of the purple bar. Great!
It would help though to have the add-on updated for Firefox 6.0.2 instead of having to open the install.rdf and change the maxversion each time a new version of Firefox comes out.

This review is for a previous version of the add-on (0.6.3.1-signed.1-signed).