Tim here. "The best Terminator movie since T2: Judgment Day" is a statement like "Jai Courtney's best-ever performance in a movie": they both have the functional shape of a compliment, but they're not actually saying very much that's complimentary. And they're both true of Terminator Genisys, the little movie that couldn't over the 4th of July weekend, and is currently on pace to be one of 2015's most visible and embarrassing box office flops.
That's not... entirely... fair. It is probably the case that Genisys gets more wrong than it gets right, starting right from that ghastly title (it's derived from an in-movie brand name designed for maximum marketing impact, but that hardly makes it less obnoxious). But it doesn't only get things wrong, and some of its successes are genuinely worth the time it will take to watch the first half of the movie on Netflix several months from now.
The plot is a jam-packed muddle, but the basic strokes are that, in the war-torn California of 2029, human resistance leader John Connor (Jason Clarke) is about to stamp out the evil artificial intelligence system Skynet, but before he can, Skynet sends an assassin robot called a T-800 (Brett Azar's body with Arnold Schwarzenegger's younger face CGI'd on) back in time to 1984.