I have tried Vimium, Vimium C, Surfing Keys, and a few others; however, Tridactyl is the best. It is comparable in terms of raw power and capability to Qutebrowser, which is remarkable. I have yet to find a use case where a Qutebrowser solution did not also work in Tridactyl. My favorite features include the `:command` mode to execute complex commands (including chaining them), the ability to use custom JavaScript, the tridactylrc file (makes it easy to sync dotfiles), the ability to control other add-ons, and the ability to control Firefox itself (i.e., clear history, local storage, etc: by time or whatever). It is without a doubt the most feature-rich Vim-like browser add-on; as a result, it also loads the slowest. It also currently has issues with Google Docs/Sheets/Drive, so you may need to use an alternative (like Vimium) for those sites. Lastly, this add-on also requires the most learning and configuration to use efficiently, as it is the most complex. In conclusion, if you are a power user who strives to abandon the mouse entirely with full control over the browser, then Tridactyl is the add-on for you. But if you just want something simple, then Vimium or Surfing Keys are always an option too.