So after watching the trailer twice (watched it once, then had some time to absorb it and then saw it again yesterday) I don't think the trailer looks great, but i don't think it looks terrible.. it's in that "OK" territory for me. I'm still cautiously optimistic and I will probably get burned, but I've seen interviews with Tim Miller and Cameron and it just feels like they're saying the right things to keep my hope alive for a bit more at least. "This will be different and more in the spirit of T1 and T2". I get that the trailer doesn't really show us that, but it was also a trailer focused on spectacle and we didn't really get much in terms of story.
What I'm getting so far and my guess for all this is that Natalia Reyes seems to be the new John Connor, maybe for whatever -plot reasons- there's been a change in history and John Connor is no longer a big threat (maybe he's dead but he doesn't seem to have a big role with the little we've heard) and Mackenzie Davis is the good terminator sent back to protect her. Gabriel Luna is the bad guy and I have a feeling maybe Sarah Connor won't show up for the first 45 minutes or so and that appearance on the highway is her entrance. How Arnie figures in, no idea, but I love Arnold so I hope we get something cool. I think the concept of an aging Terminator is interesting and sadly Genisys didn't get into it that much, but it's still an interesting idea.
Overall I think Gabriel Luna looks pretty good as a terminator, to me he has that look of a terminator. Not a super fan of them always having to come up with new terminator robots though, IMO we haven't had a truly good one since the T1000. Don't care much about him being hit and flipping away like it's a superhero movie, I mean remember that fight at the mall between Arnie and the T1000 in T2? That felt like two machines fighting.