SPOILERS FOR CAPTAIN AMERICA BELOW THIS POINT
Good movie. Liked it a lot. The fight choreo was well above average; a nice mix of parkour-ish acrobatics into the hand to hand without looking too much like wire-fu, and--maybe my favorite beat of the movie--a textbook rear naked choke on the Winter Soldier, complete with a proper lockup of the arm using your matching leg hold . I was stunned to see that, there's never good grappling in these movies. Kudos. I wish Falcon had done a bit more wingsuit melee--I'd love to see using a wing buffet into a big leap into a kick or something--but can't have everything.
The main villain plot is totally incoherent but if you just treat it as an unexplained McGuffin it worked well enough. I am suppressing my urge to come down on the side of the villains and will just say that if you actually have blink-of-a-sparrow surveillance and enough computational resources to do accurate simulations over human timescales, CONGRATULATIONS, YOU JUST WON. I suppose you can just shoot everyone you don't like, but you're a postsingularity AI, you're basically untouchable. Do whatever you want and in a way everyone will like, you can do that.
Liked the scene with Zola; unrealistic but a nice gimmick. However, characterization bothered me; they went out of the way in Captain America 1 to show him as a bit of a scaredycat who wasn't all that evil and felt uncomfortable with Hydra. Now he's actually literally a cackling villain? If this was supposed to be a revelation, it felt just poorly foreshadowed; in fact, it looked more like just poorly tracked continuity.
A few little things I loved: the Pulp Fiction joke on the tombstone, the boy who recognized the Captain at the Smithsonian, the aforementioned chokehold, "first kiss since 1945", what the hell it's Danny Pudi, Widow the matchmaker, "on your left".
A few stupid quibbles:
- Captain America goes to some lengths to avoid shooting people in the initial boat scene, goes for nonlethal takedowns, etc. Except for a handful of people he easily and intentionally knocks off the boat. Normal people aren't likely to survive that fall; if they do, they're in the open ocean at night. They all drowned painfully or maybe lasted just long enough for lethal hypothermia. HTH.
- I did the math out. If you assume a SHIELD helicarrier has comparable mass to a Nimitz, dropping one from 3,000 feet lets off gravitational potential energy about equivalent to a fiftieth of Little Boy. Congratulations, Captain America set off three peewee nukes in DC . (Let's not even ask about the ordnance and reactors.)
- I know real world business logic makes this a nonstarter, but I really think the story would have been a much more interesting conspiracy thriller if it turns out Black Widow's on Hydra's side.
- Speaking of, did ScarJo have laryngitis through the entire shoot? Her voice is way huskier than Avengers or Iron Man 2.
- Marvel's not good at dealing with the implications of one off gadgets; Mission-Impossible quality face and voice replacement isn't just a throwaway, it fundamentally rewrites spycraft.
Oh, and the stinger--I am hardly a Marvel expert but that seemed VERY interesting, most notably because my understanding is that the two featured people (Quicksilver and the Scarlet Witch) are usually classified among the X-men. That says, I am told, very interesting things given the litigious mess that is cross-studio licensing of Marvel. MCU shouldn't be able to use any X-men at all...unless something's changing.
 I fully expect some jiujitsuka to come complain to me that he crossed his ankles or didn't pull the head back properly going for the choke or some other point of detail I missed in the five seconds it was on screen; shut the fuck up. He did some legit grappling, and well enough that I was even able to recognize a detail by saying "Hey, I've done that to someone's arm when I was in the same position!" Count your blessings.