(the big city battle lost a lot of impact for me from being so similar to the one in Dark of the Moon)
Well, I haven't seen that Transformers
movie, but there were a couple of features about the Avengers
Manhattan battle that stood out for me and that I doubt would've been true of a Michael Bay action sequence:
1) The focus stayed on the characters. Although there was plenty of destruction porn, the characters of the Avengers and their particular traits remained at the forefront of our attention: Captain America inspired and led people, Widow was fearless and resourceful, Hulk was mainly in it for the smashing but came through for his teammates when it counted, etc. The most important beats weren't explosions and crashes, but character moments.
There certainly is a focus on the main TF characters, though I know for a lot of people that's not a good thing considering how... well if not hated then at least not liked a lot of the film characterisations are. I know there are a lot of fans who really don't like Prime's "Lets end this, kill 'em all" approach. I tend to veer between agreeing (he's a children's hero rather than a realistic war leader) and disagreeing (it's a logical progression, the events of the first film basically showed trying to lock up Megatron would be a fool's errand and just causes more trouble down the line).
I think what tips me towards the later is, following the previous two hours (betrayed, one of his best friends killed, told to sod off by the humans even though that leads to them nearly being all killed) Prime being exceptionally pissed off as he heads into Chicago is fairly understandable.
2) The civilians weren't ignored. The heroes' first priority, as it should be for superheroes, was to protect the innocent and rescue the endangered. Even in the middle of this huge apocalyptic battle, they were taking the time to free people trapped in buses and coordinate evacuations and rescue hostages and so on.
That doesn't translate totally though, by the time the Autobots are able to fight back (thanks to be forced off planet by the US Government) Chicago has been occupied for long enough there aren't any civilians left.
Don't get me wrong, the end of Avengers works fine. And considering the similarity of setting and that a lot of the same ILM people likely worked on both it's understandable there's a lot of bleed through on design and style up of the action scenes. It just wasn't as "Wow" as some of the previous set pieces (the Hellicarrier stuff is brilliant, and I don't think off the top of my head I've seen anything quite like it in a film before. Though now I've said that people will be able to come up with 50 of my favourite films that do) because of the "I saw a lot of this last year" feeling.
In general, I actually think the biggest achievement of the film in general Marvel terms was the rehabilitation of the Hulk. I don't think anyone was expecting the one big name character/actor not coming off the back of a recent, succesful, film to help set them up to very nearly manage to steal the whole film from Downey Jr.