The movie, although lacking a perfect story and acting, is far from terrible.
Although Christian Bale's acting had some stale parts, I thought that he captured the overall "feel" of a post-apocalyptic John Connor. On the other hand, Sam Worthington and Anton Yelchin's performance were pretty well done despite Sam Worthington's accent, which is minor.
The environment of the movie is top notch. It captured the post-apocalyptic feel extremely well (I was reminded of Fallout 3). All of the terminators were top notch, the CGI and explosions were great, and the overall gritty sense of survival is there.
Overall, if your a fan of the Terminator series, you should be in the theater right now instead of reading this review.