I really loved this film. I am a big fan of the original trilogy and I really enjoyed lots about the prequels despite their flaws. So it was a safe bet I was going to enjoy it one way or another. But I would have to say I was pleasantly surprised.
I find that I almost can't explain what I liked about it so much without contrasting it to the prequels though. So I'm just gonna own that
Yes, it was nostalgic seeing X-wings and TIE fighters again, but I would have still been cool with new designs. Same with the Death Star III, er I mean Starkiller base. It used stuff from the OT, but it used them right. Which is to say it didn't use elements illogically. So Kylo Ren has a mask and ominous black robes etc (like Vader) but it makes sense to dress up to intimidate since he has such a baby face, unlike Vader needing a mask to survive. Compare that with the jedi robes and youngling training helmets and remotes in the PT. Ben Kenobi wore desert robes, they were just his clothes. To retcon all the jedi as wearing them makes no sense and is just taking something from the OT and using it illogically. Likewise when Luke has his training on the way to Alderaan, the remote and the helmet with blast shield were just improvised tools, as cute as those younglings were ,it was stupid to have them be the "standard way of things". So yes it kept lots of classic elements but in a way made sense and, after all,
I thought the plot was fine, it might have left me curious about some unexplained things but it did flow from beat to beat. It didn't have any obvious holes to me (well one but more of an unexplained thing, see below). It had coincidences sure (Han Solo just happens to be in the neighbourhood when the Falcon takes to the skies? Yeah, right!) but that is convenience, not contradiction. Compare the fastest way from Gunga city to Theed is through the planet core at the start of the TPM but at the end the Gungans are just nearby. Same for character motivations, did Finn seem to defect conveniently quickly, yes, but it still made sense. Compare Padme's motivation for secrecy "I'm a senator" WTF? Yes jedi were forbidden to love (Oh except Ki-adi-mundi) but that's not what she says repeatedly. The biggest flaw for me (picking up on Sunder's point) is that there needed more explanation of the relationship between the New Order the Republic and the Resistance. It was touched on in Hux's speech about the Republic secretly supporting the Resistance, but just one line of dialogue would have cleared it up. That really bugs me because the plot DOES hang on that whole issue.
As for the plot just being New Hope again, it really isn't the classic heroes quest with archetypal figures so much as equal parts beats from New Hope and Empire strung into a new plot. Not a complex one but certainly not the same one as New Hope.
Did Rey seem to master the force quickly? Yes. Though she arguably had been using it all her life and was already using it to fight, pilot and perform feats of agility. Exactly like Luke who learned to block laser fire by being told "the Force exists" and "reach out with your feelings". And basically once he needed to summon his lightsaber in the Wampa's lair he could if he just relaxed. So if anything, for me it is only out of place compared with the prequels notion of years and years of formal education being necessary to learn to use the Force. A mark against them rather than TFA.
OK, what did it do so right that blew my socks off? The characters were likable and the dialogue was snappy. That was basically the magic of the originals for me. It had characters with characters traits! They did stuff and said stuff that made me laugh. Things that I believed! The relationship between Finn and Poe has more real friendship in a few scenes than Ob-wan and Anakin in three films. And the affection between Rey and Finn was light but had real chemistry, compared with the Ani/Padme totally forced, chemistry-free relationship which was mostly just him being creepy and her saying "but I'm a senator" UGH!
That's the guts of it for me, the characters. BB8 has more character than all the prequels combined and the dialogue happens organically during the action. Not action scene then exposition while character walk down a hall or sit in a circle then action the exposition etc etc.
So yes, plenty of images rehashed (Finn in gunnery cockpit just for one of hundreds) and I can see where that would just bother people. And if episodes 1-3 didn't exist it would probably bug me too, but I think I'm like a lot of old fans and that stuff was like a bacta tank for the wounds suffered at the hands of George Lucas because his ego was too massive to admit he needed the sort of help he had for ep 4.