I went and saw this the other day and thoroughly enjoyed it. It largely reminded me of stuff I used to know about Woody in the 1980s and had forgotten rather than breaking lots of new ground but it is very well done. Woody's sister is pretty cool too.
It does slightly fall down at the end by perpetuating the Match Point/Vicky Cristina Barcelona as return to form fallacy.
Talking about it with my youngest brother - he's in his early 30s - I was struck how surprised he was when I explained that up until the late '80s one might have seen every film Woody Allen had made and (a) enjoyed them; and (b) not have felt that this was the cinematic equivalent of bagging all the Munros. But he is also surprised when I explain what an event a new Robert De Niro film used to be.