As sequels go this is excellent, picking up straight after the first movie, they got the balance of Tony Starks arrogance and genius perfect. Wittily scripted, with some great action sequences, this film is about the people as much as the animated suits! One thing that is an issue is having 100s of grey battle suits fighting Iron Man at night, it bought back memories of the transformers movies...lots of fast moving metal objects, nice to see, but a tad detached as a viewing experience. Of course, in the comics , battles are a slower experience (they go at the readers pace) so I think the producers of this film have done the best they can ( as with Transformers).
Get it, enjoy it.
The Thor , Captain America and Avengers movies are yet to come. Frankly , in the last 10-12 years, I can't think of many really bad Marvel comic adaptions , possibly elements of Spiderman 3 and of course, the first Hulk film ( but the Hulk reboot was great ). I love this stuff, and if you are a comic fan or an action movie fan, you should too !