Just got back from seeing it; I enjoyed it and my sense largely parallels Morrus'. I'll have to see it again to solidify my opinion, but right now I'd put it after ESB and Star Wars, ahead of TFA, RotJ, and of course the prequels.
I think TFA did characterization better, though it's easier when they are fewer characters. R1 opened a bit slowly but still missed characterization, but it didn't suffer from the derivative plot that TFA had. Both had their callbacks, I'm mostly OK with them -- the Red and Gold squadron bits I think were essential, but Ponda Baba and R2/3PO were probably unnecessary (could have ust as easily had them in a non-speaking role in the background of a shot). Star Wars Rebels inclusions were a bit cute.
I'm OK with Vader (question: why doesn't Bacta heal Vader's burns and scars? It heals everything else in this universe?), though they could have just used him at the end instead of doing the Mustafar scene which was just a hair out of place (didn't break the movie, though).
CGI Tarkin was almost OK; with a bit more shadow they could have pulled it off. Reuse of Red/Gold leaders worked. CGI Leia was horrible and really jarring at the end of an otherwise great effects movie -- they could have stopped with the shot of her from behind and a line that said something like "Here are the plans we recovered, Princess ..."
I've liked my starfighter battle scenes the best in my Star Wars movies and this one didn't disappoint.