Excellent integration Rated 4 out of 5 stars
I installed it mainly for testing how GoogleTalk could be used from within FF. I used GTalk successfully with this extension and it really does what it says. It also provides additional functionality such as collaborative work, but I don't need this now.
It would be nice to have sounds for chat message notifications and it would also be awesome to have other IM protocols integrated (to have Gaim withing TB or FF). Custom smiley themes would also be great.
Also the interface is a bit unorganised - you actually have to install 3 or 4 extensions to get the full functionality. And I didn't find an option to log off - only to change the status to offline - not sure it the same.