Rated 2 out of 5 stars
EXCELLENT idea for an add-on, but quite buggy. 4 stars is a little overrated.
The intuitive UI is a great idea, but every time I respond to a message, it composes in plain text instead of regular old HTML.
An entire step in the setup assistant is devoted to "tweaking settings to make Thunderbird run more smoothly", and I think that detracts from the goal and purpose of the add-on. The name of the add-on is "Conversations". Why the extra crap that messes with Thunderbird?