A lot of people say the movie relies too heavily on A New Hope, and that's actually kind of nonsense. Yes, one of the main plot points revolves around a ANH-style thing (Starkiller Base vs Death Star) but that was shunted quite thoroughly into the background by the primary triple stories of self-discovery. In terms of emotional tone, I really felt this film leaned far more towards Empire than anything else, though not really. It has a different, more interesting narrative than a standard Campbellian arc. It involves the story of two heroes and a villain that are intertwined through chance and happenstance, not one young man's voyage of discovery to his power. For example, the mentor didn't die (because Han Solo was not their mentor) to propel the plot. We get flashback hints that Rey was one of the new Jedi that Kylo Ren is supposed to have destroyed - the last Jedi, perhaps. If she has a Campbellian arc awaiting her, it will be in VIII, not VII.
None of these new characters are doe-eyed innocents like the traditional Campbellian hero that Luke embodied. Each of them has their own unique backstory. Finn was a nameless Stormtrooper. Sure, he didn't want to fight anyone, but he was trained to do so. He had seen the elephant. Rey was some sort of indentured servant, with no illusions as towards the cruelty of the galaxy. Poe Dameron is a skilled combat pilot. Possibly the most innocent character was Kylo Ren, not innocent in terms of actions (for he is a murderer and a traitor) but innocent in terms of understanding the ramifications of his actions.
Lots of people are saying this movie is safe and that's silly. There's a superweapon. There should always be a superweapon. And the plot point is more interesting because that superweapon has been used as a Macguffin to weaken the Republic, so that the Resistance and the First Order are on more of an equal footing. This movie took very large risks, such as relying on Rey and Finn and Kylo Ren to drive the story. Does it hearken back to the previous films? Sure. Name me a sequel that doesn't. It should. But Han Solo doesn't drive the plot. Luke Skywalker isn't even in the damn film. Leia has a handful of lines, and it's mostly expository dialogue.
JJ also took a big risk in making this movie personal. There's very little expository dialogue about what is going on in the galaxy, and we find out only enough to ensure we understand the stakes for our individual characters, without really understanding what is the deal between the First Order, the Resistance, and the Republic. He leaves that for other movies and directors to extrapolate. Why is the Republic funding a Resistance? Is there some sort of peace treaty between the First Order and the Republic? A neutrality pact? Is the First Order a small sect or a large group of planets? All sorts of interesting political questions that haven't been even looked at, let alone resolved. Star Wars has always involved galactic politics, even in ANH, and JJ shied away from it here.
The amount of nostalgia in this film is the same as that which was in the prequels, and I'm fine with it. I was fine with Han Solo dying, because he died to introduce a new villain. I'll be fine if they blow up the Millenium Falcon (which, if they haven't considered, they really should).
In the end, I just really, really, really like this movie. It didn't recapture the childlike glee I remember from watching the original series as a kid. It was something more than that. It was aggressive, new, modern, but still visibly, emotionally, and viscerally Star Wars. It is an excellent film if you don't understand a lick of the original stuff, because while the original material is treated with a sort of reverence, understanding none of it is needed to get what is happening here. And I think that's a testament to how well JJ made this film.
I trusted him, and I was right.