I think the movie is pretty good and does not deserve the really crappy reviews it is receiving.
Here's 3 goods and 2 bads:
Goods:
1. A serious tone through the whole movie; no goofy scenes like Scotty's Willy Wonka tube ride in Star Trek.
2. The scene with the giant terminator, through the bridge scene, was very cool.
3. The Marcus character added a nice human drama to the story.
Bads:
1. The movie needed more scenes like the one where Marcus and Reese are attacked by the Terminator in the devastated city. More scenes likes this (of Terminators coming after Resistance fighters) would have given the movie a more on-the-edge-of-your-seat feel to it.
2. The ending, as people have noted, seemed a bit rushed. Another half-hour of film time might have made for a better ending.
Three out of four stars.