This is the thing you must remember about Terminator: Salvation. This is NOT about John Connor (Christian Bale). It isn't even about The Terminator. It's about a hybrid, normally a good thing nowadays but in this case, it's a bad thing. Actually, the whole movie is a bad thing. Pity it didn't stop them.
I confess to not having watched Terminator 3: Rise of the Machines. How could ANYTHING top Terminator 2: Judgment Day? That was the Godfather Part II of Terminator films (a film that was the equal or better than the original in Aragonesque). That might have helped in following all the goings-on, but I doubt it would have. After watching this film, a line from American Gangster came to mind. "Quitting while you're ahead is not the same thing as quitting", if memory serves right. Advise that should have been heeded.
The film really is about Marcus Wright, played by Sam Worthington. He agrees to sign his body over to science after his execution. Jump a few years later and we're deep within the war between humans and Skynet. Marcus wanders in, meets a young Kyle Reese (who in the future will be sent into the past to protect John Connor's mother Sarah--but who will end up being John's father...it makes sense in the first film). Marcus helps Kyle and they meet up with members of the Resistance and while saving another member we discover...SPOILER ALERT...Marcus is a MACHINE!!! He still thinks he's human, and he and John join forces to rescue Kyle (who he knows is his father via cassettes left by his mother) along with other humans from a Skynet prison in post-apocalyptic San Francisco. The Resistance is planning to destroy the machines but that will cause the deaths of those humans trapped in the prison. Are you either bored or confused by now?
The film is loud but remarkably uninteresting. Bale brings his Batman intensity (occasionally along with his Batman voice), but he's almost an afterthought, as if he had to be included because the mythology demands it. Worthington does a slightly better job, but on at least one occasion his Australian accent slipped out. The fact that Worthington (who goes out of his way to show he cannot act) can do better than someone who can is a sad and sorry sight.
Anton Yelchin (who did a good job as Chekov in Star Trek), also does a credible job as Kyle, but I'm confused. If memory serves correct, Kyle and John were about the same age when he was first sent to protect Sarah. How then can John know Kyle is his father?
Worse is the abuse of Jane Alexander. You have one of the most respected actress of her generation, and I was surprised to see was in the film. I expected her to play a wise elder or something, but all she did was look frightened and I don't think had more than twenty words of dialogue. Is that a way to treat the former head of the National Endowment for the Arts?
The effects drown out whatever story you have. You end up not caring what happens to anyone here. It's wildly inconsistent: at one point Reese reacts to music coming from a car radio as if the phonograph had just been invented, but a little later Connor is blaring You Could Be Mine from T2 to attract a machine. Which is it?
Try not to put a little inside joke. It just makes things worse.
The worse is when Bale in a voice-over talks about how this battle is won but the war goes on.
This is when the film violates one of the Golden Rules of Filmmaking: Never End Your Movie Suggesting There Will Be A Sequel. This shows either great confidence or great contempt on the part of the filmmakers. Confidence that your story is so great people will demand to know more. Contempt that your movie is so bad people won't care and will pay more to watch something equally bad or even worse. If the public rejects the work, the makers only end up looking foolish. They end up with not a movie but, to quote a review for Cleopatra, a series of coming attractions for something that will never come.
A good movie will stand on its own. A bad movie will die. A bad movie that suggests there will be a Part II will die twice. Think of truly horrible films like League of Extraordinary Gentlemen or Matrix Reloaded. Part of the reason they failed was because there was no ending, just a 'to be continued' tease. The Godfather, Spider-Man, Toy Story, or the original The Terminator, conversely, work both as films in their own right AND the first part of a longer story. The difference: there was no obvious attempt to include a suggestion of a sequel.
Ultimately, at first I thought it might be worth a rental. However, on reflection I thought, 'Since I've gone through life without watching Terminator 3, I could have gone without seeing Terminator: Salvation. I sure hope Christian Bale goes on to make a silly romantic comedy. Too much of this intensity will leave all of us asking him, "What don't you %#$@*^ understand?"