This is the 4th "Terminator" film in the series and I would have to say it is my least favorite.
"Terminator Salvation" is not a bad movie, however. There are some pretty good things in it. Sam Worthington's half human, half terminator character was very interesting. While Worthington was a big bore in "Avatar", he is very compelling in "Terminator". He was sort of like a modern day Frankenstein Monster in the fact that he didn't know what he was and where he belonged.
My biggest problem with the film was Christian Bale. "Terminator Salvation" again proves my point that Bale is one of the most overrated actors working today. I just don't like him at all. For the first time, John Connor was boring. I even prefer Nick Stahl's Connor over Bale's.
My biggest worry was I would not enjoy the film because Arnold was not in it. Instead a CG Arnold is used. The effect was convincing enough and I really enjoyed that fight scene. It was an unexpected surprise that made a good climax to the film.
"Terminator Salvation" has its problems. The film has its thrilling moments, but it is also filled with its boring moments. It is enjoyable enough, but I think the "Terminator" franchise has reached its end by this point.
C+ I recommend it.