I'm in the camp that found the first two acts pretty meh. Not bad, but nothing to cry home about. The final act however, was incredible. Everything was mmmmmmm.
It gets an A- from me. Maybe a B+. Hard to say, still amped up from that finale.
On the topic of Tarkin, my friend didn't even notice he was CGI. He only realised after the Leia scene and was like 'how did they do that?'