I really enjoyed it. I need to see it again to really get my head around it but there were a few moments that bothered me:
Starkiller base was very badly handled as a storytelling element. I almost think it would have been best to open the film with Hux's Hitler speech and the destruction of the new capitol. Then have them recharging it throughout the rest of the film, taking days rather than 15 minutes but giving us a clear timetable for its necessary destruction.
JJ Abrams seems to have crafted an implausibly convenient tiny solar system for this whole film to take place in. Since every planet seemed to be able to watch the capitol and its moons/nearby worlds blow up they must have all been closer together than we are to our closest planetary neighbors. (this kind of shit annoys the hell out of me)
I'm still not clear if Finn is force-sensitive or not.
Kylo/Ben's struggle could have been sold infinitely better with two lines and a few seconds. Have him hand the saber to Han and clearly insinuate that he needs his father to kill him because he knows he doesn't have the strength to walk back from the path he is on. Having Han refuse would further confirm to his twisted mind that the light side is inherently weaker and give him the push he needed to kill him.
For all his obfuscation and mysteries, JJ showed very clearly in the trailers and other promotional material that Poe would be back, why bother spending 2/3 of the movie pretending he died?
The ending was about as underwhelming as could be. Long cross-fading shots of Rey climbing a mountain and then more overlong shots of her and Luke looking at each other from across the top of it. At least give him a wry line to button it closed with.
I don't remember a single new theme. Hopefully the score will shine more on repeated viewing.
It just isn't a stand-alone film. Unlike Episode IV, where the history and influential events and characters were clearly important and intriguing but only ancillary to the immediate story (Clone Wars, Senate, Emperor, Luke's Father, etc.), this story is full of so many unknowns that seem designed purely to keep us guessing rather than to make the universe feel bigger than what the lens of the camera is showing us.
Overall, first viewing only, I'd put it above the prequel trilogy but far too incomplete a story to be held in the same esteem I feel for the OT.