I saw Age of Ultron this week too. Thought it was a lot better than the first. Not as tidy but had a bit more going on. Much more Whedony, has that Buffy thing of exploring the cost of being a hero. The action was pretty much the Marvel blueprint stuff but the bits between the action were more interesting than Assemble.
Ultron himself was a bit of a mess. The Scarlet Witch was a great villain though, worked very well. I thought the Avengers we're all well served TBH, maybe CA and Thor could have had more but sure they have their own films for that. Hawkeye actually felt like a character for the first time too and the new guys were well introduced.
I would say Marvel are at their best over the last year or so. Winter Soldier, GotG and Ultron are 3 of, if not the 3 best from Marvel Studios so far.