I loved the 1st trailer, I love the 2nd one too!!! To be very honest, I'm waiting for the Rogue One more than for EP VIII. There is no disappointment risk in there, we all know the story (at least at large), it's going to be a good World War II battle movie our generation 40+ so liked as kids, set in our favorite Universe.
Yeah, Darth Vader had to be there. But as said before, he will be more a looming presence. He had to be there because of public request/outcry and because it would be hard to justify leaving him out. But this film will not be about him for a change. I suspect he will have exactly the 3 sec time in the movie seen in Trailer 2 (for the time of a deep breath). As much as I would love seeing him chop down rebels big time, it's not going to happen and would not be a befitting task for him either.
I liked those scenes with the X-wings flying in the dark. And yeah, our favorite stormtroopers are back again. I hope they will have the chance to redeem themselves at least a bit (pleeeeeeeease!)