So this is the first movie with which I'm struggling with the score.
First off, it's not as bad as I remembered. It's still a poor movie, but not a disaster.
So, here's the bad stuff:
Some manic direction by Favreau. He's kind of all over the place, refusing to dwell on any plot line for too long. This is cause by and/or aggravated by a screenplay that's far too busy.
Here's an action movie that wants to tackle the following themes or storylines: Tony's fight with his own mortality; Tony's stewardship of his company; Tony's relationship with his father (and his father's legacy, which includes Vanko); the government's involvement with the Iron Man suit; SHIELD's involvement with the Iron Man suit; Tony's brotherly relationship with Rhodes; Tony's relationship with Pepper; a business rivalry between Stark and Hammer; Tony's inability to cook eggs; and so on.
It's too much, and as a result much of it is underdeveloped. The movie just kind of spins its wheels for 120 minutes, and then delivers the audience unto a numbing, perfunctory action scene -- the same denouement that threatened to spoil the first Iron Man.
So, what's the good. Well, the action and the dialog. The cast here has great chemistry. Much of the writing is clever and funny and heartfelt -- to the point where I'm sure some of it is improvised. Even as the plot went nowhere, I was interested in the relationships between and among the characters. That's nothing to sneeze at.
Some of the action is good too. While the Monaco race scene suffers from some sketchy CGI, I like the brawl involved. Watching Tony scramble for his suit, and then put it on (in one of the more bad-ass and visually inventive sequences in the MCU) was good stuff. While I really dislike the final fireworks show with an army of disposable robots, the scene of Tony and Rhodes going back-to-back and fighting together worked for me -- especially after they butted heads throughout the film. The Vanko shows up and spoils it.
So, final thought: this is a manically-directed, busily-plotted movie elevated by the charisma, conviction, and enthusiasm of its leads.
This is somewhere between a 4 and a 5. I'm going to be generous and give it a 5.