Very hard to say... On the one hand I feel that it's like comparing apples and oranges, but on the other I do feel that both The Force Awakens and Rogue One are both full-on Star Wars.
Both have that familiar setting in a universe we love with epic battles, exotic locations and a story about how good will always triumph over evil.
TFA - despite being mostly a soft reboot of the franchise by reusing a lot of stuff from ANH - was the great old fun that we're used to from Star Wars; it has great lovable - and intriguing - characters that play very well off of each other, creating humor, tension, mystery and thrills whilst giving you the fact-paced action that we're used to with lightsabers, blasters, spaceships and The Force.
Where the Prequels at times didn't feel like Star Wars, TFA really managed to capture the spirit/essence of what it meant to be a Star Wars movie - having a fun roller coaster ride that once you're finished, you want to experience again and again.
R1 on the other hand went with an original story - although it has to be said that it could've been called Fanservice the Movie (not that I mind at all, I loved it to bits, but it was clearly doing that) - and with a different tone; still Star Wars in a way, but also not.
Where TFA was more 'fun for all', this was more of a 'badass' movie - still very fun, but not in the classical way.
It was more serious and adult and gave us a new look on the Star Wars universe that we've been desperate to see (despite seeing it in books, comics and games in the EU/Legends).
Showing truly how menacing and terrible the Empire was (something only hinted at in the OT) as well as all-powerful and controlling (really felt the nazi vibes with the constant patrols, check-ups, etc.) is something that was very welcome.
Also very cool was the fact that we see a different side of the Rebels; a universe where there is more grey areas than truly Light or Dark Side, which gives it a more realistic feel.
Yet the characters (despite not being one-dimensional) didn't feel as alive as in TFA and felt more 'on track'; like a James Bond movie where they had to hit the points they had to, to get to where they needed to be.
In TFA it felt more like a natural journey where our heroes weren't sure where they would end up eventually.
But this is what I mean; what is Star Wars?
An argument can be made that it is fun for people of all ages, telling a 'simple' story of good vs. evil wrapped in a space opera jacket with elements of spirituality thrown in there to balance out the sci-fi with fantasy - being more magical than realistic.
Yet R1 totally felt natural to this universe and despite there not being the 'normal' amounts of humor or plain fun, it was still badass.
Again, I feel like it's comparing apples and oranges; like putting 'Prince of Egypt' and 'Finding Nemo' next to each other; both amazingly awesome movies, but totally different tone-wise and what they're trying to achieve.
So yeah... I still don't know; on the one hand TFA felt more like a true Star Wars movie because of its characters and emotional journey and therefore the better movie, but it wasn't as original and unlike Rogue One, that last space battle was almost forgettable next to this one.
But then Rogue One relies heavily on fanservice and - although it being an original story - didn't feel as much fun (in the classical Star Wars way with a space opera that's pure epicness) and more like a gritty war movie that was just badass to watch.
I think the best way to put it in words is like this; TFA felt like an 'adventure movie' and R1 felt like an 'action movie'.
Both are extremely alike - and great at what they do - but there are small differences that make it hard to compare them.
TFA was the classic hero's journey which was more magical and wonderful, while R1 was a mission or eye-witness account of soldiers during wartime that felt more realistic and rough.
Both are amazing and both definitely are Star Wars, but it's hard to say which is better; in any case I liked both way more than the Prequels.
That is to say, ROTS felt Star Wars, but there were too many small annoyances (Anakin's turn to the Dark Side was way too rushed amongst other smaller things) that made TFA and R1 feel like the better movies.
The first 2 movies didn't feel fun in any way, be it badass or marvellous and as for the OT; I don't want to put TFA or R1 above ANH or ROTJ (ESB is the Holy Grail and untouchable), but they are definitely on-par in my opinion