Re: Optimus Prime's characterization (Spoilers)
^ Pretty much well said. After seeing all the chaos that had gone down, I think any good man or autobot for that matter would totally lose it after seeing his fellow friends get hurt and even lose their life.
I actually enjoy seeing Optimus get all heroic into the killing machine he was in ROTF and the Chicago seen in DOTM. Yeah unlike his usual character we're familiar with but makes you want to cheer him when he does that in the live action movies.