Rated 3 out of 5 stars

The key feature I was looking for was to have all of my conversation, including sent messages and deleted messages, available whenever a new message came in for a conversation. This saves me from having to keep messages lying around in my inbox just because someone *might* respond to a previous message and continue the conversation. This plugin delivers on that front. Yeah!

What I don't like is the way it radically changes the UI. The Gmail UI that it imposes on you is not bad, but it clashes with Thunderbird's existing UI. For example, I *like* TB's tree view of conversations better than Gmail's flat view. The changed interface also makes it hard to find the reply-all and forward buttons (it actually DISABLES TB's native buttons for conversations with more than one message in them). It would be nice if it gave you a choice: classic TB vs. Gmail interface. The developer clearly spent a lot of time working on the interface; sorry to be so negative about it, but if I wanted Gmail, I'd use their web interface instead of TB.

This extension also slows down TB, a lot. Whether that slowdown is due to the conversation indexing engine or the UI, I don't know, but it is irritating.

I'm keeping it turned on for now, until I get used to the trade-offs. We'll see whether I keep it on.

This review is for a previous version of the add-on (2.1.1).