Went in and watched it without high expectations, I was still a bit disappointed , the movie felt so different to the first two, that it seemed to me it didn't fit. I found myself bored for the first hour or so while the plot was being set up.
Ironhide's death caused by Sentinel Prime's betrayal came to me as a shock and big surprise, didn't really see that one coming.
My biggest gripe by far is Starscream's death, come on, death by two humans?!?! That feels so demeaning of the character who's been in an important role in the first two movies. Even Shockwave, who was an epic disappointment (that guy basically didn't do anything), got the honour of being killed by Optimus Prime.
Then there's Megatron, who doesn't get much screen time at all, he didn't do much either, with the main villain being Sentinel. That was disappointing too, Megatron joins the fight for a few mins right at the end and gets easily killed by Optimus Prime immediately. I found myself wondering, why did they bother...
Also didn't like the alien spaceships, it doesn't feel very Transformers to me, it feels like another generic alien invasion technique (for lack of a better term). Shockwave's worm thing (Driller) was lame, the building being destroyed in half was lame, the Stealth Force modes were lame (to me anyway, the transition to the big screen wasn't as great as I expected) and Sam should have died a dozen times already with all the situations he's been in (especially when the Orbital Spaceship thing crashed with him on top).
I think the biggest problem for me was that the action didn't justify the movie like it did for ROTF, in terms of just the action, explosions and what was happening in the climax of the film, I felt DOTM was worse. A few scenes I couldn't follow what was happening, probably coz I didn't pay enough attention.
I was surprised at all the (brutal) deaths in this one, and finally more Autobots died instead of only just Decepticons. It was quite cool that there were quite a few references to other aspects of Transformers.
Oh, and we didn't get to see Optimus put on his Jetpack transforming from the trailer, I was looking forward to a scene like that and would have loved it but it wasn't to be... The ending was very abrupt too, so quick that I was like, "Huh?! It's finished!?".
Overall, I think it's worth watching, but DOTM was the only one in the Trilogy where I walked out after watching and felt disappointed. The first movie is by far the BEST, while I can't decide whether ROTF or DOTM is better (ROTF has better action sequences, while DOTM is more coherent). Really really really annoyed by Starscream's and Megatron's death though.
"sometimes the things you see might not be real and the things that are real you might not see"