For what they are I enjoyed these films. Just don't expect too much because there is a little bit of hype (especially around the first film) that isn't particularly warranted. Good but by no means great would be my verdict. I actually enjoyed Russian Dolls more than the first film, but despite this I found my contempt for the lead character grew, and by the end of Russian Dolls I just couldn't take Xavier seriously any more. He truly is beyond frustrating. Audrey Tautou is excellent as his ex girlfriend Martine, but she serves no purpose in the second film whatsoever, other than to highlight what a weak man Xavier actually is. Martine is an interesting character, a curious mixture of contradictions that might have been an excellent lead character in a different film, but it is just too difficult to believe that she would have any role in Xavier's life after the way she has treated him. She has an awful streak in here that no man would tolerate.
Big credit to Cédric Klapisch for making the sequel so enjoyable despite the epic frustration surrounding the lead character, he certainly got great performances out of Kelly Reilly, Kevin Bishop & Cécile de France. I don't really see how the third film Casse-tête chinois (Chinese Puzzle) could be either necessary or any good, but I felt that way about Russian Dolls so on that basis I will happily go to the cinema and watch it when it is finally released here in the UK. I trust Klapisch to somehow make a good film against all odds although I can't even begin to imagine how annoying Xavier is going to be by the time he hits 40. The mind boggles.