I would rank this the third best Transformers movie I've seen. That's not a compliment.
Michael Bay's 2007 movie had a ton of problems--way too long, poor Transformer designs, unwelcome and uninteresting humans, weak comic relief--but I thought it was more than redeemed by the final action sequence in the city. There was no spatial or temporal logic to the editing, but the way the Transformers themselves blended into the live action environment was the most impossibly amazing thing I'd ever seen.
Two years later, the Transformers are still the most awesome special effect you'll see this summer, but it's just not enough. All of the first movie's faults are still there and now magnified because, the second time around, I'm naturally going to have far less patience. It's also plain worse in every respect--running time even longer, annoying humans more plentiful, comic relief more incessant and less funny, plot holes more numerous. And while Bay seems reluctant to draw upon the much superior classic Transformer designs, the ludicrous and convoluted plot feels very much like a vintage cartoon. In fact, in its senselessness and audiovisual loudness, it's almost like a live-action version of the 1986 animated movie, except that it's been made twice as long by padding the runtime with inane plots and repulsive characters. And this is another one of those frustrating cases where the fanservice doesn't seem to realize that it's fanservice, as in the case of the prominently featured yet unrecognizably limp Devastator.
None of this is to say that I hated the movie. There were still cool moments, such as the opening action sequence and the fight in the forest. For the home video release, I think it would be great to offer an abbreviated cut. Heck, just take the action sequences from both Bay flicks and compress them into one feature, because, even though I enjoyed them to an extent, I would never want to watch the entirety of either movie ever again.