It's emotion. After having seen it for the first of many times yesterday, I have to say this was a TF movie on a more emotional level than all 3 other movies. When a autobot died in this film, it was actually hard to watch (Ratchet and even Leadfoot. Hell, I thought Brains being tortured in that chamber in order to comply with the humans was fucking harsh). And for the first time EVER, when a random human character dies..people in the movie actually care. We never got a scene similar to Lucas's death scene before in the TF movies. Easily the darkest scene, really in all 4 movies. Yeah, we saw people in chicago get vaporized but they NEVER touched on that it just went straight to "find the girlfriend. shoot the pillar down". The dead of Chicago were only really given attention in AOE. But Lucas...I felt he didn't deserve that, especially given how he was the one who was in the most fear for his life. And then you legitimately felt Optimus and his autobots' rage towards humans as it's continuously highlighted how sick and tired they are of them. Overall this movie makes the last 3 look like a joke.