Never did a movie series have so much potential that was squandered so mercilessly. Watching all six is an interesting lesson in how a premise can be improved on, while at the same time, some heights are impossible to reach again.
It almost seems like a cruel joke to take somebody who has the most oversized personality in the world and give him the job of playing an emotionless robot, but Arnold is so committed to the part that it comes off just as well as any of his more typically gregarious performances. It's a budget masterpiece with an excellent script that wisely never spends too long dealing with the "technical" side because it understands that the real point is the thrill of the pursuit by an unstoppable enemy.
It's certainly not a great film on its own, but it's also not nearly the disappointment it's been made out to be, especially compared to half of the series. It has a good premise and a good setting, as well as some fine actors. It just never manages to be as engrossing as the better Terminators.
What characterizes this movie the most is a lack of invention. It has exactly the same premise as its predecessor, but with uninspired casting and God-awful jokes. It does have an unexpected ending, but that's not the same thing as having a good ending, or being worthy of getting made.
I often see it suggested that this is the best Terminator movie since T2. I'm sorry, the 21st century movies may all be disappointing, but don't be blinded by that. This movie sucks. The only one worse is Genisys.
A movie that had no right to be made. Zero imagination, terrible acting and a repetitive script that contributes nothing to the overall story. Watch this movie if you want to witness a franchise spinning its wheels in desperation.