There is one reason why this film is worth your money, and only one...

Rating: 7/10 (23 May 2009)

And that one reason is the Arnold guest appearance. I can honestly say I have no idea how they did that. That sure did not look like a CGI face to me and he was entered into the film seamlessly, and the five min that he is in, and terminator beat playing in the back, just made the whole film worth while.
Other then that the action felt like a hit and miss. Some action scenes were grade A, like this action set piece in the water and the ending fight with the T-800, while other action set pieces, like the truck scene, just seemed to drag. Maybe the adds gave to much of that scene away so it couldn't surprise me like it should have.
The other problem I had at least is the humans seemed to be doing to well in this war. The flash forwards in the other films showed them on the brink of death, living off of rats and pure smarts, but in this they had jets and submarines at their finger tips, and because of this I never got the feeling that man kind was a step shy of dieing out.
Still, none the less the characters were well done, and when an action scene does get hit right, it goes out of the park.
The lowest in the series, but still a good part to the series.
PS. The PG-13 doesn't hurt the film at all. All the blood that was needed was in it. Adding any more would have just seemed forced.