I watched The Terminator after it completed its initial run, at a midnight showing in a California theater. I had avoided it because it sounded bloody awful. But I still get chills remembering that first viewing. I think the movie was one of the best science fiction films ever made. This was largely because it presented an idea that is almost alien to modern, secularized Christian civilization: the idea of inescapable fate. At the end of the movie, the pregnant Sarah Connor sits in her jeep, and the Mexican gas station attendant says "a storm is coming." Sarah, knowing the world is about to be blown to bits by a conscious computer, and that her son is mankind's only hope, looks down the road and says: "I know." Wow.
The second Terminator movie was not nearly so good because it Christianized the basic plot. Redemption (in advance of the fall itself) seemed possible at the end. Still, it was a very good film. The third put the story back on track, but was poorly cast and had little of the power of the first two films.
So what about the third? Well, it's better than number three. Christian Bale is fine as John Connor. Sam Worthington is more than fine as the cyborg who thinks he's human. The theme of robots who switch sides and fight for humanity is constant through the last three films. This is the best case, for the Marcus Wright character was human once: that makes it possible to play with questions about what it means to be human, and to be given a chance to redeem oneself.
Terminator Salvation has a lot of goofy plot twists, and confused story arc, but it is a very watchable film. For the first time we see the presence of Skynet, the computer trying to wipe out human beings (Helena Bonham Carter), and that was probably a mistake. When, in Lord of the Rings, do we ever see Sauron's facial expressions? But it is a mostly derivative film. We don't get any of the sense of fate that made the original movie immortal.
Worst of all, they didn't get the original musical score. We are constantly teased with music that sounds like the original, but it never quite consummates the great theme that was there for the first three movies. I am sure this was some Hollywood negotiation gone bad, but for heaven's sake! Couldn't the filmmakers have cut some kind of deal?
If you like the T-series go see this one. You won't be sorry you did. But you will be frustrated.