Freaking awesome movie! The special effects are incredible, the action is amazing and everything works on all cylinders. The new character cyborg guy was absolutely amazing. Make no mistake, this is his story, not John Connor's. And you will be glad because this actor from Australia is incredible. It's like watching Hugh Jackman play Wolverine for the first time. This guy has a great career ahead of him. The Arnold Schwarzennegger CGI is pretty good. Not perfect, but pretty good. Once that T-800 starts ripping the place apart you will have a renewed respect for that model.
These movies just keep getting better and better! It's amazing that one little blurry flashback from the first film can make for such an epic romance/adventure tale. It looks gorgeous, it is well acted, it has great action. Don't go in expecting too many scares. In this series vampires and werewolves are fully fleshed out characters, not things to make you jump. Probably the best description I can give you is Spartacus crossed with Romeo & Juliet with fangs.