I've been using vi-like shortcut plugins (vimperator, pentadactyl, vimium, vim vixen and many others, currently using tridactyl) for quite a few years now, and its never been quite the smooth experience I hoped for.

Not even talking about interfaces where you'd expect to need to use mouse (javascript components and others), but there is always the page in which the shortcuts will fail, or some input which will be blocked because the plugin is fighting the webpage for focus. Its pretty much what the article says at the conclusion, it helps reducing, but I still view it as a hassle.

Browsers developed with vi-like modes built-in (vimprobable, vimb, qutebrowser) fared better for me, but then there's other issues like incompatibility or lack of plugins which keeps me from fully using them.