Yeah, on the whole not as good as the first half of the first movie but maybe better than the second half. (Really Iron Man's origin is his strongest story. Oddly, in the original comic it's told pretty poorly -- that's what you get when you give a Stan Lee/Jack Kirby plot to Larry Lieber and Don Heck.)
I've seen critics whine that there are too many subplots, but I think they may just have ADD. It all fits together pretty neatly IMO. And of course everyone always bitches when a superhero movie has more than one villain (because that totally ruined The Dark Knight, and, um, Iron Man 1), but Hammer and Whiplash are pretty complementary and both very well-played.
Plenty of Easter Eggs out there (the [spoiler]"I'll take Secretary of Defense"[/spoiler] line, and is the element he synthesizes supposed to be Vibranium? Because if so, that adds another layer to the gag in that scene) but not terribly distracting. The world-building works too; Fury's got a bigger role in this one but it doesn't distract from the main plot.
Cheadle's a better actor than Howard but on the whole I think Howard was a better Rhodey. Cheadle's no slouch, of course.
EDIT: Also, this movie has the worst technobabble I've heard since
Die Hard 4. Who the hell says "cycles per second" instead of "frequency"?
But fortunately, if your system is compromised (because someone hacked the mainframe, of course), all you have to do is reboot and that'll fix everything.
