Hey everyone, I just got back from Paris so I'm here to do an update. I got the regular JUC.
It's correct that France prices are similar to US prices after the VAT refund, so imo it's not really worth it to shop in France unless you live in a state with high sales tax (which I do). Additionally, unless you get it at the airport duty free, there's a possibility you don't get the VAT refund. I've heard horror stories about the store not filling out the VAT refund correctly and long lines at the airport to get the VAT refund.
Individual stores get a higher VAT back than department stores. 12% vs 10.8%. I really enjoyed the Rue de la Paix store. That's probably my favorite Cartier store in Paris, and I highly recommend it. Their service is excellent and the store has many beautiful high jewelry pieces to admire. I also went to the Galleries Lafayette store and their service was not as good plus the lines were very long.
Is it still worth it to get Cartier in Paris? I'd say yes, because its a piece I've been wanting that reminds me of my first trip to Paris. The savings are not that great though but better than nothing.