I saw it... 5 times already! Yeah, I love the Transformers.
This movie is an incredible theatrical experience. I would not rate it better than the first Transformers movie (2007), however the 3D in this movie is impressive and immersive. I saw the IMAX 3D version yesterday in Montreal and it blew me away. The transformations in 3D are so awesome.
I haven't seen a movie that provides intense excitement and wonderful action at the same level as this one in a long time.
The story is very good also, better than the second movie. There are major plot twists that surprised me. And I just love the connections they make with the Apollo 11 mission!
I second your recommendation to see it in 3D, but I will add that if you have the chance to see it in IMAX 3D, jump on the occasion. It's definitely worth the extra cost.
After five viewings, I'm still pumped about it. It gets better with every viewing! I might surpass my current record of the movie I've seen the most times in the theatre (Transformers in 2007 - 12 times).