Me as well, went in with high expectation, from the Net ratings, and hearing from a cousin who don't really like Tom Cruise's acting before this saying it's good.
Luckily, managed to adjust expectation after the less than bombastic opening scene (before the opening credit) by recalling Brad Bird's previous works in The Iron Giant, The Incredibles and Ratatouille, where characters interaction & development is more important, action scenes are used (and done well) only when really fit in the story, and humour plays a part even when the situation is deadly serious.

Then I starts to appreciate the main difference in this 4th installment;