Bloody terrible! It broke everything! This will take me literally days to fix. If I could give it negative stars, I would. Fortunately, the minimum is 1-star, which it doesn't deserve.
Firstly, it won't stop duplicating contacts, including placing many of them outside of any group. The moment I merge the duplicates, they are recreated. This is annoying and completely defeats the purpose of sharing groups.
Much more serious, however, is that the contact ID (or whatever the Google API calls the unique contacts) is getting changed. I have other software that depends on these IDs and everything is breaking! I now have client files without a client, no clue what has to be done, etc.
Why the hell would the contact IDs be changed?!? There's absolutely no reason for this.
I've sent an email to customer support; nothing. Their chat also doesn't work. I'm going back to the terrible (but won't-break-anything) delegated contacts provided by Google.
Long story short: if you have ANY other app communicating with G Suite Contacts, this will break it (eg: RingCentral, Vonage, Clio, SalesForce etc).
This needs fixing ASAP.