Rated 4 out of 5 stars
This is not a separate add on, it is a search engine addition the same as the one on Mycroft. Although you do have the option to have an extra search box on your toolbar if you want, you don't need it.
This did give me a pretty comprehensive list of hard to find torrents, with the most recent and healthiest at the top. However, it doesn't list the number of Seeders so I probably won't use it much. Clicking on each link to find out if it's healthy is annoying. (I miss Isohunt!)