Overall I thought Abrams/Kasdan pulled off a really good and definitely most entertaining space opera. I mean, it was really fun to watch.
I have some issues that maybe will be smoothed out by more viewings, or not.
I went spoiler free (I knew about the general premise of the First Order vs. a "Resistance" and deduced a few things from the trailers, but that's it), and with Kasdan at the helm I was expecting to be surprised and even pleasantly shocked, much like I was with ESB (and ROTJ). Being surprised by where the story went was always a big aspect of SW for me. But my big surprise turned out to be how unsurprising the movie was, almost from start to finish, and my biggest shock was how safe they've chosen to play it. Not all the surprises in SW were good ones (especially in the prequels) but with this new chapter with a few exceptions there wasn't any. It feels a lot, too much I think, like the OT with more modern cinematography, and the script cannibalize dANH's to a surprising degree.
Some of that was expected as Star Wars always had a symphonic structure, with the episodes being built of variants on the same themes and ingredients (parallels, echoes, variations, mirror effects etc.) - in fact I was afraid that Abrams might throw that down the drain, not go a bit too far in the opposite direction...
With GL it was for the most part never particularly subtle, but on the whole Lucas and his writers managed to keep it fresh, in part because Lucas mastered the mythology behind the plot and archetypal characters. It wasn't always good, but it didn't feel like recycling.
With the new episode though... it feels more like Abrams/Kasdan have re-arranged the partition for new instruments rather than have the courage to write a genuine new movement for the symphony.
My hope was that Kasdan, being a better writer would pull off better than Lucas did the challenge of throwing us into a different era of the GFFA, with new issues and settings, with new characters beside the old ones in secondary roles - and still make it feel like SW. Lucas did manage well to offer a SW world radically different than the OT, but he wasn't as successful at preserving the fun/goofy aspect of the OT. I was disappointed that Kasdan opted for 2-hour of fan service instead, giving the audience was they expected without much effort put on inventing something new for the sequel era that we didn't know yet we'd love to see. It's a great script, and it's a great movie, but with no risk taking whatsoever. Lucas took huge risks (knowingly, he anticipated the backlash even before TPM came out) and went against expectations, stubbornly stayed on track despite criticism from the fan base. He partly succeeded, partly failed, but TFA did not even try... it removed from the saga all the irritants from the prequels then essentially remade ANH with bits of ESB/ROTJ thrown in.
Anyway... concretely my main gripes are with the recycling of the "fallen Jedi" story line and the "kid found on a desert planet" story line. I was hoping that Kasdan/Abrams would find another way to continue the family saga, as between Anakin's rise and fall and redemption and Luke's arc it seems to me the circle was complete and all that truly is interesting in that story has already been used. To make it worse, they also seemed to recycle Palpatine, given Kylo Ren a big boss of the "puppeteer" type.
They might still surprise me in the next episodes if they've decided to go the route of "let's start in the very familiar before going elsewhere altogether", but I'll keep my expectations low. I hope at least they're not intending to offer us another "redemption" act with Kylo Ren, and I wouldn't want to be in the shoes of the writers who will have to come up with a convincing backstory to explain how the son of Leia Organa and nephew of Luke Skywalker, could possibly end up worshipping Darth Vader and ignoring his redemption, strive to continue his Sith legacy... For now we know Ben had daddy issues and appears psychologically/emotionally unstable, but still...
The only good clue comes from Adam Driver, who says that Kylo Ren doesn't see himself as evil but as doing the right thing. I suppose he became convinced somehow that the Jedi were always evil and responsible for the war and chaos (the old lies spread by Palpatine, rejected by the Rebellion born of people who knew better like Bail Organa) and Luke and Leia are not heroes but the villains that destroyed Vader's cause and legacy and maybe who went as far as pretending to Kylo that Vader betrayed the Sith in the end (clearly either Kylo doesn't know or more likely does not believe this to be true), but that still doesn't explain how Ben Solo could become so deluded about what really happened, nor why he would grow to hate his family and all they stand for so much that he would make his mission to destroy them and what they fought for all their lives. We can surmise he was not exactly raised in circles very sympathetic to imperial propaganda... We'll see what they come up with, but I'm skeptical it won't disappoint.
Another hope is that they won't recycle for Rey the "dangers of being seduced to the Dark Side" arc. We've seen both sides more than enough already. Could we move on to other angles for the Dark vs. Light conflict, please? Another hope for Rey is that she won't turn out to have been "hidden for her own safety" by her loving family. I'm hoping Maz had it right that those she was waiting for would never come back to Jakku for her, that she was either abandoned there by someone who feared her emerging powers (and thus she's probably not a Skywalker) or else that if she's Luke's daughter she is believed to have been killed in the attack on his "academy" but in fact was kidnapped and abandoned on Jakku by a younger Kylo Ren who didn't have the balls to simply kill the little girl.
The other source of disappointment/irritation was the serious lack of exposition to put the movie in a larger context. As you point out Cannoli, that's probably motivated largely by the PT. Even ANH had more context than this, and it wasn't a lot. It wouldn't have taken much more either in TFA to put a bit of meat on the bone and make the context more enjoyable (and make it feel less confusing/simplistic).
From what I understand, a year or so after Endor and the death of Palpatine, the main remnants of the Empire were soundly defeated on Jakku and the disunited remnants scattered to the outer regions, while at the core a New Republic rose. Eventually Snoke managed to regroup enough imperial remnants to resurrect the Empire's mission as The First Order, as a rival entity to the Republic, but not yet at war with it.
I'm not sure where the "Resistance" is coming from, though. Why aren't they the Republic's military? Why is that movement openly opposed to the First Order so small? When did it start? Why is someone like Leia at the head of the resistance instead of part of the Republic? Is the Resistance purely a continuation of a rebellion that never shed the arms, or is it a rebirth after years when the rebellion no longer existed?
My guess for now is that the Rebels and their allies founded the New Republic after the "final" defeat of the Empire, and that the Resistance is a new movement born out of the New Republic many years after Endor, either in response to the apparition on the scene of the First Order and its dark sider Snoke or maybe even linked to the slaughter of Luke's students, which might have happened at the same time as the First Order became openly hostile after years of "cold war", and their hostilty might have been triggered by Luke's attempt to resurrect the Jedi Order.
I can only guess that the New Republic might have been hoping to be left out of the conflict with by refusing to declare war proactively against the First Order, hoping to co-exist in peace - and then a group of opponents centered on Leia Organa and a bunch of old Rebel leaders like Ackbar founded the Resistance to oppose the FO, without official support from the Republic, and with minimal resources. That would make the Republic as stupid and blind as the Old one, if not worse... but hopefully with one of their systems wiped out by the FO the Republic will now join the war.
All that said, for the most part Abrams and Kasdan pulled it off. The new characters are fun. I'm on the fence with Rey, as I'm not quite yet sure how she'll differ from Luke, Obi-Wan and Anakin in the role of the "Jedi apprentice" (with bits of Padmé thrown in) and they've really not helped it by making her an orphan on a desert planet... But we'll see. For now let's say that in an all too familiar role the actress was quite good, and now it's a matter of giving her a good arc. Finn was fun, mixing a bit of Luke with just a bit of Jar-Jar's goofiness and cowardice. Poe left me a bit colder as a kind of mix of Han and Leia. I could have done without Kylo being yet another fallen Jedi and Leia's son, but Adam Driver is great and the character has a lot of potential. I'm eager to see where they'll be going with Luke, and to discover more about the circumstances of how and why he tried to bring back the Jedi Order, and why the fall of Ben Solo led him to vanish. What was he trying to achieve, put an end to the war because his own efforts to bring back the Jedi Order was the cause of the First Order's attack in the first place? It sounds a bit like a foolish move, given that the other side is lead by dark siders...