Ok, I saw this Saturday night in IMAX in NYC, so here goes.
I should note first that I rewatched IM the night before. I paid more attention to Shield's presence and Howard as Rhodey, because I didn't feel Shield was an issue in IM, and I wasn't too keen on Howard so I wanted a better comparison to Cheadle. I'll start by saying that I prefer Howard over Cheadle, not that Cheadle wasn't good as Rhodey, but I enjoyed Howard's take; it felt more relatable and not as distant as Cheadle did for me. Minor thing.
Now as for all the nitpicks I've been reading by film critics and board members here, I didn't find any of them. The pacing of the film was fine, but felt slightly lacking as IM did, I watched the deleted/extended scenes after IM the night before and thought a lot would have been helpful to strengthen the film a little bit more. I'll say the same for IM2 knowing that we have 30 minutes of unused footage. Again, overall, minor issue.
The cast was great all around, action was awesome although fast paced and hard to keep up with visually sometimes, but enjoyable nonetheless. I didn't feel the Avengers/Shield integration was any more or less bothersome than in IM, but rather felt it tied in better this time around. All the little nods/easter eggs were great and didn't distract in the slightest. Black Widow's part made more sense after the whole party scene.
Now as for Whiplash...I enjoyed him, but in all honesty preferred Rockwell as Hammer as a "villain". WL was too reserved, and I wish his physical part in the final battle was longer, but then again being up against two iron men...it makes sense he went out as fast as he did. I'm just glad that the whole chase sequence with the drones and WM lead right into it, otherwise it would have felt like a rehashed, rushed weak fight like the end of IM, which wasn't as bad upon my re-viewing the night before.
I'd say Rockwell was the scene stealer, and I'm glad his character is still around, albeit in handcuffs. The only thing I didn't like was the end scene with the medals; it felt like Star Wars in a way, and it just ends. I don't know, it felt a little bleek after the sort of cliff hanger ending from IM.
Still, overall, the film was solid, had a great balance of action/comedy/drama, etc, and was fun and enjoyable. A more noteable reference to the 10 rings would have been great (even a mention about the passport guy), but no biggie. I give it 9/10.