Thank you for the spoiler-free review. I've tried to stay away from reviews in general, but the consensus seems to be that this is a good Marvel film, though not nearly the best.
I've also heard about the gut punch, and I am also somewhat skeptical. Like you said, nobody ever stays dead in the comics, which is something that always annoyed me. You can have all the great death scenes you want, but they become cheap when you know that this character is just going to come back again. I'm not saying that I necessarily like it when everyone dies (not a huge fan of GoT for this reason), but there should be an actual threat of death to give the proceedings a certain amount of tension; even if nobody actually dies, it's different when you know that somebody could die.