Just saw this today at IMAX, I liked it.
Pros:
+ Ratchet's whole scene and death scene (CRY EVERTIM)
+ The general tone, different from the other 3
+ Better characters, Drift was cool, like most of the Autobot cast
+ Better human characters, not awkward like the past films, Cade Yaeger was a fantastic character
+ No Shia LeBouff
+ Good humour, such as Drift's irony
+ Galvatron's voice- perfect
+ I liked the idea of humans improving upon cybertronian tech with transformium- though the morphing thing makes for bad toys, the concept was great
+ Dinobots being rebellious powerhouses
+ The dinobots being lifted up by Lockdown's ship, especially Slug. Looked cute.
Cons:
- Galvatron and Stinger being invincible with his morphing abilites, then suddenly being able to be slaughtered easily, along with all the vehicons.
- Optimus somehow being able to reformat and fix himself after all the crap about needing the Autobots needing to fix him.
- Bingbing Lee
- The dinobots not talking (though I hope the 5th movie focuses on the dinobots' minds and development as characters)
- The dinobots being big, scary set pieces, rather than characters. You'd think the Knights of Cybertron would be pretty wise and honourable instead of ferocious beasts.
- After a small battle with Optimus, the dinobots just decide to do what he says. The battle should have been longer.
Overall, pretty good film. 7/10 for me. Not perfect, but not a bad film. Better than ROTF and DOTM, but not as good as the 2007 movie. ;)