Piece of advice : Watch the movie without any preconceived notions.
Overall: As a fan of sci-fi action, I really enjoyed this movie.
Effects: The effects were top notch. The Harvester machine sequence looked great.
Characters: The character development felt rushed (and in some cases, non-existent). Christian Bale did a solid job as John Connor, but his script could have used more depth. Much of his time on screen is in action sequences, which understandably, makes it hard to progress the character.
Storyline: If you are looking for answers to questions raised from previous films, put those to the side and wait for the next one.