Long story short, it's a messy time travel story with unclear rules and an inconsistent tone. It spends far too much time on callbacks to previous films and doesn't really have that many great lines/moments of its own. The big final battle had some cool spectacle but it was a bit too overcrowded for my taste.
Iron Man, Cap, Hulk and Scarlet Witch got some cool - albeit very predictable - moments but I was disappointed not to get a Hulk fight scene and I hated what they did to Thor (if they needed to nerf him there were way better ways of doing it than making him a fat slob that's still somehow worthy).
I'm also still confused about what's been done to the timeline.
- The world and snap survivors are five years older than everyone that was brought back?
- Cap traveled back and lived a full life in this timeline which nobody remembers?
- Loki's alive but that's an alternate timeline?
- Hulk decided not to resurrect Vision, Heimdall, Quicksilver etc?