Mixed bag for me but I enjoyed it overall and feel good dipping out of the Marvel movies after this. That said, Infinity War was significantly better.
Spoilery notes (in no particular order):
I think my favorite was Stark being distraught over what happened to Spidey being the impetus for him changing his mind and then hugging Parker on the battlefield after he got desnappified. Their weird surrogate father/son relationship has been one of the nice things they've altered/expanded on for the MCU. Also the nicknames will be what I miss most (Blue Meanie, Build-a-Bear, Lebowski, etc.).
Also liked Thor. The Dadbod of Thunder/Lebowski goof was fun for a while. He moped for maybe a scene or two too long but I largely enjoyed his arc and liked that they put him with the Guardians at the end.
Didn't care much for the Back to the Future II "replaying the old movies" Time Heist section. While it was nice as a "historical review" of the franchise, it largely boiled down to a series of "Hey remember THIS?!" easter eggs and to sneak in some cameos. Robert Redford gots to get paid.
Also didn't care for the mopey first thirty minutes. Obviously that's where the narrative had to go and it's supposed to make the reveal at the end where everyone comes back that much more fulfilling but it didn't really add anything that the end of Infinity War hadn't already accomplished for me.
Cap wielding Mjolnir was a nice touch (since Dadbod Thor apparently can't even take out un-gauntleted Thanos after more or less one-shotting him at the end of Infinity War with the full complement of stones... I know, plot convenience) and a great way to wrap up his character arc.
Also enjoyed Scarlet Witch's moment in the end battle. Don't screw with a lady's robot fucktoy.
Everyone suddenly being able to handle the infinity stones (after it was established in Guardians and other movies that holding one would insta-gib you if you weren't incredibly powerful) was... convenient. Stark in particular being able to handle the full array after it took 4 Guardians to handle the Power stone and the gauntlet brought Hulk to his knees. I mean it's nit picky comic book guy bullshit but this movie was chockful of that kind of cheap narrative convenience.
Captain Marvel being gone for 95% of the movie was also very convenient. I guess that's a way to solve the "Superman conundrum" (how do you write around an invincible, omnipotent hero?): just remove her from the movie. Probably for the better. From the press junkets and interviews, it seemed like Brie Larson didn't make many friends among the cast.
I particularly enjoyed how Stark died quietly with no quips or sappy death speeches (apart from the convenient living will/wrap up narration after the fact) and that his last words were a call back to the beginning of the MCU. Nice touch.
My wife got all weepy about Cap getting to not die a virgin and live happily ever after with his 1940s sweetheart. So thumbs up from her, I guess. Just don't think too long about what that means for the timeline.
All in all, satisfying character arc endings for Stark and Cap and a solid landing for this ridiculous 11 years of movies which is all they really needed to accomplish. The narrative specifics were a little shaky and they could've trimmed out 20-30 minutes of fat but everybody got their scene and the main characters got to walk away gracefully.
