Saw it today and it was great. The big fight between all the Avengers was one of the best superhero fight scenes I've seen. That alone was worth the price of admission.
I loved the introduction of Spider-man. It was perfect, and Tom Holland was adorable. The Marvel Studios Spider-Man movie is now at the top of my anticipated list. Black Panther was introduced well too.
Really the only disappointing thing was Captain America didn't get a tremendous amount of development. This was as much Iron Man 4 as it was Captain America 3. It felt more like Tony's story and we are only seeing it through Cap's perspective. I guess this was a Captain America movie since Bucky played a central role to the plot and Cap led one side of the Civil War, but that was really the only reason his name was on it.
I loved the twist at the end that led you to believe it would (SPOILER)take the typical route of the superheroes making nice to fight the big bad but then it switched things up on you and (SPOILER)led to the rift between Tony and Cap growing even bigger. I know there are critiques of Zemo as the villain but what he tried to do made sense in the end and his motivations for it were believable. Not every villain has to get some big super weapon and threaten the world to be effective.