I just checked the GitHub page for Tridactyl, it seems to have so many features. Do you have any frequently used feature that only Tridactyl provides but not Vimium-FF?

There was a HN post[0] recently about that, you can find more insights reading the comments. I went from vim-vixen to vimium then to tridactyl. As for features that only Tridactyl provides (things may have change in the meantime) I must say that I absolutely love their hinting mode. It's totally different from anything I have used (even qutebrowser's which is completely keyboard focused [1]). It also provides a desktop executable that allows you to edit everything in Vim. That said, I've been using it for 6 months and I know I only scratched the surface.

0: https://news.ycombinator.com/item?id=24615787

1: https://news.ycombinator.com/item?id=24636160

sure. i think the big ones are all kind of related: - a proper commandline, not just "open url / search" field - everything's an excmd. you can compose them and write your own. you can bind them to keys or use them adhoc. - you can define excmds that execute javascript snippets - ~/.config/tridactylrc

(oops, those are supposed to be bullet points. seems it's too late to edit now.)