I'll be straightforward.
The movie was incredible. It rivals Star Trek for sheer fun. Testament to how good I thought it was? I watched it twice. Last time I watched a movie in the theater more than once? Return of the King.
It's no Lord of the Rings, but Michael Bay knows his military, knows how to blow things up, and makes a really great Transformers film.
Like Star Trek, it's not without a couple of logical inconsistencies which will stretch your ability to suspend disbelief, but not to the extent where it will affect your ability to enjoy the film.
Several things I'd like to bring up about the movie, trying to avoid as many spoilers as possible.
First, Soundwave. I love how he was given the form of a spy and communication satellite. And I enjoyed his status as the Decepticon tactical coordinator. And I liked that he survived to cause trouble in the next movie. Best of all, he was voiced by Frank Welker. I didn't like that he didn't say "Ravage, eject," and that Ravage was a casualty. Then again, that just means Laserbeak is coming.
Second, more robotic asskicking. The Autobot vs Decepticon combat in this movie was ramped up to the nth degree compared to the first movie. Best part was that Optimus Prime was the one who did the best fighting, up to and including dual-wielding energy-enhanced blades versus three Decepticons (best fight in the movie).
Third, more Transformers. Hooray for bringing in Arcee(s), Devastator (the real one), Jetfire, Soundwave and Sideswipe. Boo to not having Sunstreaker (he and Sideswipe are bros, dammit), Shockwave (really, big, gun), and Grimlock (Spielberg! Jurassic Park! Grimlock bridges both movies!).
Lastly, and people who watched the first film will understand what a big thing this is... They made Agent Simmons cool. I won't go into details how. But he was the coolest human in the movie. Salutes to the authors.
Watch it. Get the DVD. Then bring on another sequel.