Rated 1 out of 5 stars

Too many bugs to be useful. Duplications, empty groups, missing entries, etc.

This review is for a previous version of the add-on (0.3.3). 

If you'd be willing to make a forum post (http://pirules.org/forum/) I'd be happy to try and work through these issues with you. Those "empty" groups are present in Gmail as well if you look. Google requires that every account has "System Groups" (My Contacts, Coworkers, Family, Friends). These groups cannot be deleted. Also, by default gContactSync will sync all of your contacts. Those duplicates are probably just duplicates that you have in Gmail if you look under "Other Contacts" as well. I cannot comment on the "missing entries" without more detail.