I thought this was very funny in places and beautifully acted across the board. I've never really been that impressed by Scarlet but she did well with a couple of very meaty monologues. Her scenes with Laura Dern (who was impeccable and basically playing a more controlled version of Renata Klein) were my favourites in the movie predictably.
It did feel very stagey and over-written in places, particularly in Driver and Johanssen's big blow-out scene near the end. I guess that's how pretentious New York theatre types might actually talk to each other, though.
My main complaint is that it all could've felt so much more urgent and interesting had they both not been coming from a place of extreme wealth and privilege, which the movie touches on very briefly but never really addressed. It made it hard to care much when their problems were so superficial and easily resolved. Also neither of them were especially likable, though I'm pretty sure that's the point.
Finally, I have no idea what movie ScarJo's mother thought she was in, but it was an entirely different one to everybody else. I was kind of digging it.
I predict this will over-perform at the Oscars purely because all the rich Hollywood types who vote will have lived a version of it.