The extension offers a lot of useful features, but it severely affected my Firefox performance immediately after installation. The browser became noticeably slower, and C.P.U. usage spiked by ~35%. From what I’ve seen in other reviews, the developer tends to dismiss, and deny these performance issues rather than investigating, or assisting affected users; replying with responses in denial, instead of looking into the issue. Unfortunately, due to these problems and the lack of constructive support, I cannot recommend this extension.