The script was a major dog in this movie. Upon rewatching the film, it's clear these are different characters, not the same ones in the first. There's too much babble in this movie about topics only drugged out college kids and professors would discuss, not real people. It gets absolutely ridiculous after a while. Also, Marvel is hurting their movies having the superheroes be worried about every single innocent person. These heroes would be thanked in real life for their service, not chastised and condemned. Civilians condemn the Avengers for the lives of a few people dying in spite of the fact the villains were either trying to take over the entire world and kill a lot more or outright destroy it completely. It's ridiculous. The humans have no ability to control these superheroes either; they are Gods. They would answer to them, not the other way around. Like most babble from college types, it's just not grounded in reality, but more the result of ultra-privileged, sheltered lives and a lack of a willingness to understand how the average person operates.

The CGI model of Ultron was incredibly bad and made it hard to take him seriously. It was cartoonish, a total hack job. There's a reason they largely kept him out of the trailers. Not sure who was responsible for that, corporate hacks or whatever, but it really hurt the film.