It seems I just mentioned that I'm cynical about Hollywood filmmakers resurrecting beloved characters in slapdash efforts to vacuum money out of the suckers' pockets. Sometimes that works for me (Star Trek, Rocky) and sometimes it doesn't, like here.
In fact, I am kind of at a loss to even describe the plot premise. The series has gone back and forth in time over and over. Associated paradoxes, multiple timelines. Multiple actors playing the same character. The only constant is our old friend Arnold, who plays Good Terminator once again here. I'm just not sure where he came from.
Suffice it to say: there's a Bad Terminator relentlessly pursuing the Good Guys. The Good Guys are on a quest to avoid Armageddon, and in order to do that, something needs to be blown up. Along the way there is considerable amounts of gunplay, explosions, crashes, yelling of "get down". And someone says "I'll be back" and "Come with me if you want to live".
"Hasta la Vista"? I could have missed it. I don't think so.
Executive summary: special effects are great, J. K. Simmons is great, everything else is mediocre.