better together Rated 4 out of 5 stars

This is a great addon, however, it does somewhat partial job. When opening an individual contact, we still get a new window which limits the navigation. There would be a great way of fixing this, if doubleclicking a contact in AddressBookTab would open a contact in Contact Tabs. If the searchbox of Contact Tabs would be available in AddressBookTab, it would also help sorting out the outstanding issue of TB that you cannot find someone e.g. by phone number. Please consider - talk to each other guys.

Thunderbird 5 Rated 5 out of 5 stars

I would like to second Grzegorz_P: this is an excellent add-on and I came to love it during my 3.1; however, I started using the new version quite early as it is reasonably stable and with the conversations and compose add-ons it looks like a completely new generation email client - but it is badly missing a tab which I can have open all the time with my address book(s).

This review is for a previous version of the add-on (1.4.1). 

Done. A week that I've tested and modified it for TB5... just forget to put it on AMO.