I saw this movie with two other adults and three boys ages 8 - 11. While it did not stand out as anything special even in its genre, it was still entertaining. There were a few events that made my wife jump and many things that had us laughing, almost all of them with the movie, not at it. ;)
I would also note though that the three boys had a great time and gave it 3 3/4, 4 and 4 1/2 stars. The 8 year old found a couple scenes a little scary, but not so bad he didn't stay sitting with the older boys or was scared after the scene was over. Overall it may not be worth seeing it with your friends, except maybe in matinee, but a solid choice to go see with the kids.
Far exceeded my expectations, and those are high for any comic adaptation these days. The history 'rewrites' were faithful to the original in general theme and content and Robert Downey Jr was spectacular as Tony Stark. If I had any criticism for the movie it would be on the final fight scene, which was very well done but somehow felt a tad ... incomplete? It wasn't a let-down, but maybe wasn't quite up to the rest of this otherwise brilliant movie.