Just to list my thoughts during the end of the third act:
-I can't believe they had the stones to kill ALL of the characters. Jyn, Cassian, Baze, Chirrut, K-2SO, and Bodhi. Hats off Disney and Lucasfilm, you crossed a bridge I didn't think you could.
-Wait a second.... *Star Destroyer comes in* HOLY **** well that light cruiser that just crashed into that Star Destroyer is doneskis. Wait, Vader? Boarding party? I have a GREAT feeling about this.
Praise be The Force, this is the Star Wars film I have been waiting for. It's a complete war film, with loss and sacrifice, desperation, and coming to terms with the finality of one's death.
Again, I have to applaud Lucasfilm/Disney for having the stones to kill off all of the characters. Donnie Yen was decent. Wen Jiang was pretty meh IMO until his final sequence. Ben Mendholson was pretty great, though I missed his dialogue from the trailer which was not in the movie. Diego Luna's speech before they leave Yavin IV felt like it came from someone who had tried to rationalize his actions but came to despise himself and just couldn't live with himself anymore, well done. Felicity Jones was fantastic as well. The stand out of the entire film though was K-2SO, Alan Tudyk. It was like he channeled his inner Wash from Firefly.
CGI Tarkin was pretty great, though it did appear at times that it wasn't quite real but that passed quickly. Gold Leader was pretty great as well, and it felt like he was touched up with his scenes from A New Hope. Vader's line of not choking on your aspirations was cheesy as hell, and I don't think they hit the voice just right as it definitely sounds like an older James Earl Jones which was different from the Vader voice we had on Rebels last season.
The third act is probably the best of any Star Wars movie. The ground fight felt real and frantic. The space battle was excellent. The hammerhead ramming the disabled Star Destroyer and ramming it into the gate was genius.
Things I didn't like immediately after seeing it were few. Older Saw (Forest Whitaker) was just paranoid to borderline nuts. Yes, it was stated on Rebels that Saw is more militant and violent but nuts... Not so much. Until they went to Eadu, something felt off and I can't put my finger on it to describe why. I didn't care about Bodhi, so when he died I was like meh, and the same with Baze. I actually liked Chirrut more than either of them.
Edit: Also minor gripe about the score. At times it felt good, and hit the right nostalgia for a Star Wars film. At other times, the music really stuck out and didn't seem like it belonged. Overall, I think it was a good score but other than the theme that I don't know the name of that played numerous times in the film, nothing is particularly memorable.