I loved watching this and I still feel great about it a day later. I like all of the terminator movies and the TV series, some parts more than others, but they're all enjoyable to me. I was very leery of Jai, but other than being a bit too buff he was ok as Reese. He wasn't the complete charisma black hole he usually is. Emilia was great as Sarah but damn is she super tiny. Not that Hamilton was a giant or anything. She was very small too. Arnold was actually good rather than looking like a confused grandpa. There was some humor. The action was awesome. Future War, finally! The Arnold versus old Arnold was great. The T-1000 kicked ass and got pwned satisfactorily. They hit beats from the first two movies in new ways that were fun and the John turned Herald of Skynet was a good decision.
I don't know where they get the people for test audiences but my theatre thought the film was great fun and there was no reason to spoil the John turn. They need to not let producers panic and meddle so much or farm out trailers to people unrelated to the production. If I were the director, I'd make sure the trailer was made by MY people, the people actually involved with the film. Hollywood needs to go back to trailers that didn't try to spoil everything by giving a blow by blow cliffs notes of the plot.
Anyway, I really hope they get to make the sequels because I want to see where the altered timelines end up. The temporal shenanigans weren't hard to follow and it was cool that they actually tried to think through the impact of multiple competing timeline incursions.
All around a very fun movie.
I'd probably rank them as follows
The Terminator
Terminator 2: Judgement Day
Terminator: The Sarah Connor Chronicles
Terminator: Genisys
Terminator: Salvation
Terminator 3: Rise of the Machines
Oh, and the complaints about the 'Genisys' spelling are pretty lame now since it turns out that's the in universe marketing name for the killer app hiding Skynet in the new 2017 Judgement Day plot, not Skynet trying to be kool.
I will say I would have loved to see Joe Morton reprise the Dyson role, especially since when the character appears he'd be Morton's age now, anyway. Somehow including Lance Henriksen in the 2017 scenes as like a deputy chief would also have been great, as Lance makes everything better. Both characters survived in the altered timeline, btw. Also, they should have CGIed young Bill Paxton into the Observatory scene. The young Arnold CGI was amazing. I thought for sure some of those shots had to be animatronic they looked so tactile.