I don't know where to start on Transformers 3. I have so few good things to say about it but it seems rude to start with the bad. Hmm...
Let's start with the length. Transformers 3 is two hours and twenty six minutes long. Really. I suspect that every human being that made the decision to see the movie was not influenced at all by running time, so they could have saved a third or a quarter of the budget by making it 30-45 minutes shorter. Simple economics. And much more merciful to the viewer.
How about product placement? Every computer shown was a Lenovo; every router was a Cisco. Every beverage had a brand name showing and they even took us to the Mercedes Benz website. Enough.
The major badbots have a case of talking-villain syndrome. They each say too much of their plans to the good guys, to their henchbots or even when they talk to themselves. It's laughable. The screenwriter needs to take a remedial course in exposition. Oh, and who thought it was a good idea to have the badbot voiced by Leonard Nimoy quote dialog by Mr Spock? Campy...
Then, there's Chicago. The last 45 minutes or so was an extended battle scene that essentially destroys downtown Chicago. The bad guys were implementing their final plan and could have set up shop anywhere on the planet, an unpopulated, defensible area maybe, but no, they chose Chicago for no apparent reason. Most of the sequence was just explosion-porn, which is fine, but too much is too much.
Here's something neither good nor bad. The leading lady, replacing Megan Fox, is basically a lookalike for Megan Fox. Since she's not playing the same character, they really didn't have to stick with the same image, but it's fine that they did. During the destroy-Chicago sequence, the leading lady went from wearing 4" heels to flats and back to heels sometimes in the same scene. The fact that I had enough time to focus on her footware says a little something about the Chicago sequence.
How about some good? There is some good in Transformers 3. The same leading lady with the heels does more to win the battle with her brain than all of the autobots and Army guys combined. The cheesecake in a Transformers movie turns out to be a good role model for young girls. Whoda thunk?
All-in-all, Transformers 3 is pretty much the movie that you have already imagined it to be, only longer, louder and less coherent. There is a place for such movies, but be cautious if you think this is the blow-'em-up movie for you. It has none of the heart of the first one and might not even be as good as the second one (and the second one wasn't very good at all).
2:26; released in 3D; viewed in 2D