Rated 2 out of 5 stars

Don't understand...
It works like a champ in Google Chrome, and find it very usefull in Gmail, but it refuse to work on Firefox for me.
eg: tried to change shortcut keys without success, and no contextual menu in gmail for instance.
I continue to like it in Chrome browser

Rated 5 out of 5 stars

Works great! Too bad for the dev that the add-on got bad reviews because of the users' ignorance!
The add-on wouldn't turn on automatically when you focus on a textarea - that would be disastrous for custom UI controls.
Instead, you simply right-click and select 'Edit with wasavi', and ho! Your innocent textarea just turned into a giant beast!

Works perfectly, but the defaults are horrible Rated 5 out of 5 stars

From all the other reviews, I see that people are unable to even start the plugin.

This happened to me as well, on a Mac. It's just that Ctrl+Enter doesn't seem to be recognized as a valid keypress.
I just opened the options, and set it up to automatically open on focus. Alternatively, you can change the shortcut.

Of course, you should disable the plugin on sites with custom UI controls - e.g. Google, facebook.

Other than that, the plugin is a work of art.
It's maybe the most well-functioning and advanced vim clone I've seen yet.