Not really a Captain America movie as much as the close of an Avengers trilogy, Captain America: Civil War was great fun. My only question is whether the premise is more flawed than permissible. All action films have flawed premises that anchor the plot, but we accept them if they are plausible and fit in well with the characters. Civil War begins with the idea that The Avengers need oversight.
OK, I can see that. For all your good intentions and the scary powers of the bad guys, should there be some actual consideration given to whether the course of action you've (The Avengers) have chosen is the wisest? Look at it in the context of the previous films.
In 1, Loki has alien warriors primed to wreak havoc over the globe, the people in charge make the excruciating decision to nuke them out of existence and accept the casualties. But for some reason, Iron Man gets the final say. Just because a decision works out doesn't make it right. Why was that Tony Stark's call?
In 2, Cap is going to risk Sokovia being dropped from on high and possible destroy the human race rather than make the decision to accept casualties. Stupid. Who is he to make that call? His super soldier serum does not convey unearthly wisdom as far as I know. He justifies tis because he values the spirit of togetherness or something, but the human race may have held a different opinion.
Now, in Civil War, it comes back to bite them when the Scarlet Witch accidentally kills people in the line of duty, so General Ross and the whole world demand accountability. This makes a good deal of sense given the history, but Cap will have none of it. He can't accept control and goes rogue. This is the part I have trouble with. Steve Rogers is a soldier and has always put his country first, now suddenly he will not accept the due process his country wants to impose. Really? Wouldn't Tony Stark be the one more likely to self-justify going rogue. Rogers says they are still the best ones to make those decisions. I'm not sure I buy this sudden attraction to Platonic Utopianism. The only source of this I could see would be if the Shield fiasco tainted him for life. Nope, it strains the edge of plausibility given the characters involved.
That, for me, hovered over the whole movie and took a bit the the immersive joy out of it. But apart from that it was the usual Avengers movie, that is to say it was a blast. And, encouragingly, Spider Man stole the show, to the point that I am looking forward to his first proper Marvel movie. (If we could fold Deadpool into this we might achieve trigger the singularity.) Robert Downey Jr. also excelled too, he was given the meatiest storyline and made the most of it.
With this series it's easy to get jaded. You expect a top five action film every time out and so when you get it, you take it for granted. Like the previous films, this one is state of the art -- one of the best. In a world where sequels are factory-driven cash grabs, the Marvel Cinematic Universe has been a stunning achievement.