Okay, so let me get started. The movie is a good, solid 8/10. Not too long, and is far more tonally consistent than infinity war, and a far better movie in my eyes. The action is good, and the story for the most part is good.
But what the movie does to Thor and Captain America almost ruins it for me. Thor, despite being more comedy relief, has gone an arc in the last two movies that has been wasted now. Thor would never leave his kingdom, and Captain America's problem is far more egregious. Essentially, the timeline has become fucked because of Cap. The movie, the more and more you think about it, makes no sense.
But when it works, it works. It's probably the best Avengers movie. It's got a lot of heart, it's funny when it should be, and it's tonally better.
Good movie.