The final fight between Captain America and Iron Man was the only thing that I greatly enjoyed and seemed to fit with the theme of the movie. The rest of it (like the airport brawl) was fun to watch, but it wasn't as intense as it should have been.
Also, the setup seemed to be a little longer than needed, considering how quickly everything came to an end.
There were several characters which had perfect motives to join either Tony Stark/Steve Rogers (Vision, Hawkeye, Black Panther) but there were also others which seemed to join simply because they were the first person to ask them about it (Spiderman, Antman). Should I also mention that I hate teenager Spiderman?
For the good parts I was extremely surprised (and excited) at Black Panther's apparition and honestly didn't know he was going to have a significant story arc in the movie. Bucharest also looked awfully perfect.