If you love comic books and all of the films that contribute towards this, then it's for you. I only liked Thor of those films and it's just not at that level.
Overall it just lacks Whedon's touch. There are a few geeky moments that make you smile, but not enough of of them. The action verges into Transformers territory for sheer length at one point, but is ok.
Think of it as a superior Iron Man film and you may enjoy it more than I did.