Rated 4 out of 5 stars

I have been using this extension for at least 2 years with success. Unfortunately, few days ago, as soon as I installed TB version 52.0 (final release), I got a problem caused by gContactSync both using its "official" 2.0.11 version and also its developmental version 3.00alpha4.
The problem is that I can't drag and drop anymore contacts from an addressbook into mailing list(s) both for the "GMail synced addresssbook" and also for all the other addressbooks I have.
So I had to inactivate gContactSync at the moment, unless when I need to sync my Google Contacts otherwise I cannot assign contacts to mailing list(s) and/or I need to move contacts from an addressbook to another one.
I hope that it could be possible to patch this annoying bug.

This review is for a previous version of the add-on (2.0.11). 

I uploaded versions 2.0.12 and 3.0.0a5 with a fix for Thunderbird 52.0. Thanks for letting me know and providing a translation!

Rated 5 out of 5 stars

I use this addon to syncronize my 6 device (3 with Android using Google contacts) and 3 with Windows 7 (work and home desktop and notebook) using Mozilla TB.
Besides I suggested this app also to my wife who has 2 Android devices with Google contacts and her notebook running TB.
No problem at all with text fields of the contacts. I had only occasional problems with some photos of the contacts which disappear or duplicate in the local (TB) database.
Please note that I also use among the other extensions (more then 20) MoreFunctionForAddressbook and I have a contact list of 410 persons on my Google account on GMail.
A last note: I have no mailing list on my GMail contact list.

This review is for a previous version of the add-on (1.1.1).