I like the potential for this extension. It works well because it's blocked bad pup sites. It's also simple and easy to use. The only ongoing issue is every time I CLOSE Firefox, it crashes the browser. "Process error". (It leaves open an old FF process running in the background) I know it's the extension because when I uninstall it...the browser no longer crashes on closing. I will continue to use this extension because it seems lightweight and works, but the crashes are just an inconvenience.