Rated 3 out of 5 stars
Josh Geenen (Developer) on August 16, 2011 "These e-mail addresses are only stored locally in Thunderbird to work around mailing list bugs/assumptions in Thunderbird. They will never get propagated to your Google contactss" --- >>
This is definitely unclear. Where in the settings does it offer a "Read Only" option? This is THE main reason I do not even want to experiment with gContactSync, much less rely on it. Google is way too integrated into my life for an add-on to screw it up.
If you'd like to make a forum (http://pirules.org/forum/index.php) post I would be happy to answer any questions you may have in more detail. A review is supposed to be a review of the add-on from someone who has used it; not a question or personal statement ;)
Thunderbird doesn't allow having contacts without e-mail addresses in mailing lists. So in order to sync contacts in Google's groups with mailing lists, gContactSync has to add fake e-mail addresses to Thunderbird. These e-mail addresses are ugly, but they will never show up outside of Thunderbird (not on your phone, in Gmail, etc.). More detail in the FAQ: http://www.pirules.org/extensions/gcontactsync/faq.php#dummy_email
There is a read-only option for synchronizing contacts in the main "Accounts" window (under the gContactSync menu). Select the address book to synchronize, set up the account and group(s) to sync with it, then check "Show advanced settings" and pick "Read-only..." as the direction for synchronization.