I just got back from seeing this, and I think it was pretty good. Almost as good as The Winter Soldier, I'd say.
Initial minor criticisms:
1. The film totally ground to a halt in the middle for the scenes where Tony went to recruit Spider-Man. Killed the whole pacing.
2. The Vision totally vanished for most of the big superhero fight at the airport, only showing up for brief bits where he was necessary for the plot. Thinking maybe the filmmakers didn't quite know what to do with him.
The ending leaves things in an interesting place that doesn't feel at all like a set up for Infinity War.
It essentially sets up Secret Avengers, much like the comic Civil War.