I connected with the film, perhaps because I was going through a similar situation when I watched it (knowing the relationship had dwindled but both too naive to commit to breaking up). I am skeptical as to whether I would have connected with it otherwise... but it's definitely not worth a revisit. Most of the acting was flat but it held my attention nonetheless. 3/4's of the way in you just want it to be over.
The premise was interesting but I didn't really enjoy this movie as I was annoyed by both of the leads and didn't really care about the fate of their "experiment". Also, there were more than a few moments where the scene pacing fell apart, the seder dinner scene comes to mind.
Not altogether able to evade its own trying-too-hard-ness, but enough true moments and sarcastic humour in this to make it immensely endearing. Agreed on the parents perhaps getting a bit too much screentime, though -- Wein's character in particular comes off becoming primarily defined through his mother and father, although maybe that's the point.
In trying to fictionalize, and therefore unnecessarily construct too big a chunk of their own lives, Daryl and Zoe seem to spend more time tacking up the edges of their intended vision than actually living it. However, the film is often miraculous in its subtler scenes, that unfortunately happen too little and too late.