Hmmm. Tricky one. I would say that the comedy moments and the more fantastical action scenes (flying, big action scenes etc) did remind me tonally, to some extent, of the more colourful nature of X3. That's probably the touch of Vaughn, who embraces that aspect more than Singer. And also because comic book movies are now more 'confident' in the material rather than toning it down too much.
At other times it seemed more Singer-like, particulary emphasised by the re-creation of an X1 scene.
Story-wise, some small things mentioned/implied in X1 and X2 are contradicted (though only fans will notice/remember/nitpick) and the opening scene of X3 is contradicted (along with the end of Wolverine).
Overall, it felt like it belonged to the same franchise as all the films, but there are obviously attempts to align it more to the earlier films through its running time, pacing, more fully-explored story and the re-creation of a key scene that tells the audience this is intended as a return to the older values of the franchise.