Watching the reaction videos to the trailers on youtube. Vader-boners abound.
Oddly enough as much as I like the second trailer I very much preferred the first one. I think the Vader cameo right at the end was a big part of it, but also the music hit me in a slightly different way - it sounded epic and tragic and heart wrenching.
The new trailer gives us the hope angle, which is awesome; after likely 20 years of defeats and setbacks the fightback finally starts here. But I am constantly reminding myself that all of Rogue One are probably going to perish, even though their mission succeeds. I can't imagine anything harder than giving your life to a cause, never knowing - only hoping - that your contribution made the critical difference between victory and defeat.
I think I would have loved a shot of one of the superlaser channels powering up, like we saw in SW and Jedi. It's strongly implied in both trailers that the laser is fired; either as a "low powered" test or some kind of malfunction or the result of sabotage, it doesn't destroy its target planet but punches a feck off big hole in it.
Think it would have been cool to tease the audience with a Death Star firing sequence, or even at the end of the trailer you just hear those infamous, resonating words: "commence firing ignition".