This Vim modeled addon has the most features for a power user, it have more of a learning curve than say, Vimium if you want to utilize the additional capabilities.

How to actually browse the internet

The addon is brilliant!
I prefer it to Vimium as 'F' works on tabs where Vimium wouldn't even register them.

Very well made extension. Easy to customize. Nice dev support. After some time it becomes impossible to use Firefox without.