I just rewatched this.. huh. Didn't remember this being so meh.

Iron Man kept going down in quality and this was pretty much unwatchable. The twist does not work and the main villain is not great. Even the invention of Iron Man's suit this time is not effective and in the past Tony was cocky and levelheaded but here his actions makes his look stupid instead. The whole multiple suits also were shown as villains in Iron Man 2 so seeing them again here does not work. The presumable death of Potts was so unbelievable specially given Tony's reaction for Happy's accident.