Wired.com put together a wonderful piece on Terminator 4 with plenty of images. McG is interviewed throughout the article and, there’s no doubt, the man has mastered Terminator. 

I agree with McG point of view on using real robots instead of CGI: 

“A lot of people make CG movies where actors are emoting to poles with tennis balls on top of them,” said McG. “That’s the last thing I wanted to do. I don’t like dealing with cartoons, so to speak. I wanted real robots for the actors to interface with so you could get that grittiness and realism. There’s an archetype shape to the T-800. We needed body types to suggest the robot that would combat John Connor, and Roland Kickinger is a good body type. His shoulders are huge, his waist is narrow. The [Industrial Light & Magic] guys used their calipers to measure shoulder spatial differences and said he’d make a good body double. Roland as an individual is not in the movie.”