Acceptable, well-executed, poorly scripted.

Rating: 7/10 (9 May 2013)

Fun to watch for the most part; standard Iron Man formula; powerful business exec with a history with Tony relies on the tech of others to pose a threat.
The plot seems to wander aimlessly, not really fleshing out the main villain aside from simply that he wants revenge, giving Rhodes little to do other than be a target, inserting feel-good bit child characters; this is a badly done plot that hopes to redeem itself by its flashy and impressive action scenes, which themselves fall short of the other three iron man films.
Overall; go ahead and watch it if you liked the second film. At this point, you'll still be fine just watching the first one, and then watching Avengers.
***Spoilers below*** Three business executives with chips on their shoulders. Three threats using both Tony's and someone else's tech. Three iron man movies.
This one has the worst villain; the one that is the least fleshed out, and having the only redeeming value of a sense of theatrics.
The iron man suits have been rebuilt out of paper mache; and have a disturbing habit of completely (temporarily)shutting down if you apply heat to them.
The villains supposedly have two abilities; regeneration and heat generation that must stay well below 3000 degrees or it risks causing them to explode. These, supposedly, explain how they are able to tear apart an iron man suit with their bare hands. (For the more scientifically minded, in order to get the alloyed iron man suit to break apart that quickly, you'd need to be using a material that was itself at or above the boiling point of the metal, otherwise the absolute best you could manage would be to slowly push your hand through it; something fatal against a suit that is in fact superhumanly strong and equipped with weapons that can kill you in one hit; and we've established that getting that hot is fatal to these people)
They have no ranged weapons capable of damaging an iron man suit, and yet do surprisingly well against the legion of Iron Men; each of which is able to destroy them in a single shot to the head or torso.
In the end, there is only one conclusion; the enemies were in fact magic-users that could generate more heat than they were capable of surviving, able to generate temperatures at which their own nervous systems would be so much vapor and their supposed limits would cause them to explode without hindrance. In addition, all of that assumed, the Iron Man suits that were destroyed so easily were programmed with some sort of secretive Lemming protocol, given the command to ensure plenty died so long as enough were around to do the job.
Why did Tony build the legion of iron men? Obviously in the event of another alien invasion; that squad of 40 flying suits could likely last for days against the sort of invasion that happened in new york; considering how well a single suit did, they might be able to deal with the whole thing on their own, especially with the interesting upgrades some of them had. The movie implies that before the opening sequence, Tony was smart, and dealt with his nightmares by preparing for them as best he could. And then at the end? All that preparation, tools that might well save the human race? If I were an alien watching from orbit, I'd invade the day after Iron Man crushed the fire mages. Maybe just a few minutes.