I loved the first one and was very disappointed in the second. I had great hopes for this when Shane Black on board, and I'm pleased to say that they were realised.
While this movie had as many potential pitfalls as 2 - large supporting cast, second chap in metal suit, the novelty wearing off, RDJ out of the suit for large periods of time - Black and his co-writer Drew Pearce held it together a lot better than did Favreau and Justin Theroux.
Guy Pearce's character could have been a clone of Sam Rockwell's but while I like Rockwell, he didn't work for me in IM2; Pearce, however, was great fun, despite his initial somewhat OTT appearance. Former 24 alumni James Badge Dale did a lot of good stuff with a character who somehow ought to have been less memorable than he was, if you know what I mean! The Mandarin's depiction will alienate as many viewers as entertain but I thought Kingsley's performance was brilliant and ticked all the boxes it was meant to tick.
Black's decision to take Stark out of the suit(s) for so long worked well, as he knows how to get a great performance from his leading man and really mine his charm (exhibit A - Kiss Kiss Bang Bang). The movie had definite Lethal Weapon/ Last Boy Scout vibes at time. Black's comments that it would be like a Tom Clancy political thriller weren't too far off the mark, though it reminded me of a more fantastic 24 at times - not just the Dale involvement but the climactic scenes too.
I've no hesitation in voting Excellent.