Another reason for people think the movie focused way too much on Tony is because when Tony says he is Iron Man, it feels apocryphal. The Iron Man itself became a character, completely separate from Stark. This is especially true for the Mark 42, which played out much like the robot helper
in the first two installments. So instead of Tony being Iron Man, a lot of the movie made it feel like the Mark 42 was a sidekick.
A lot of people also agree that Iron Man 3 feels like a buddy cop movie more than an Iron Man flick, which kinda makes me a sad panda. But because of that, one of the things I liked about it was the chemistry between RDJ and Don Cheadle. I guess we should've expected it since this was a movie from the Lethal Weapon and Kiss Kiss Bang Bang guy. The up-side to that is that Iron Man 3 had a lot of funny moments. Jon Fav and Shane Black don't have the same humor and I would like to think Iron Man 3's a little funnier than the other two, but not by much.
Gets a little spoilery from here on out. So, if you haven't seen it, get outta here.
Another thing that really ticked me off is the Mandarin twist. In the trailers, Mandarin was so interesting; he was a legitimate threat and the way we thought they handled him was perfect for comic book and casual fan alike. Every Iron Man fan wanted to see the great showdown between Iron Man and The Mandarin, to see the conclusion to the "ten rings" angle from the first movie. But nope, we get whatever the hell it was we got in Iron Man 3.
Although to be fair, the only people who were irked with it are comic book nerds like me. To the broader audience, it was a good twist.
Plot holes, there were a bunch of them. If you're not nitpicky, then they might go unnoticed, but when you get a minute or two to think about it, it'll dawn on you and you'll realize how things would've played out differently had the characters used a little bit of common sense. House Party protocol could've been called in at any time J.A.R.V.I.S. was active, even before the time Tony went all McGyver on Mandarin's goons. He could've had a fresh unit by the time he stormed the mansion and none of that shit would've been necessary. There are a couple more but it'll be a pain listing them all down.
Special geek out moment for me was when Tony put on the Silver Centurion suit. That was sweet.
TL:DR: Iron Man > Iron Man 3 = Iron Man 2. That's just me, though, and I liked Iron Man 2. I'd give it 3.8 out of 5. Go watch it in the cinemas once, then get it on Blu-Ray when it's out.