Comparing them side by side, the 770 is wider and farther away sounding, but I think the nighthawk has a more “3d” or speakerlike presentation with it’s soundstage. The nighthawks strange signature is very present when you compare it to something more traditional sounding like the 770. I would actually say that the nighthawk can have more impact and extension with certain songs compared to the 770, but I think the 770’s bass is a bit more controlled with some music. If you give the 770 enough power, it can be boomier then the nighthawk, but idk if that’s a good thing or not. The midrange is sweeter on the nighthawk, but only for certain genre, where the 770 is a bit more traditional in that regard. For treble I think the nighthawk is darker and more laid back, where the 770 is a bit more forward in that regard. But that being said, the nighthawk is more detailed to my ears. The nighthawk is actually a bit easier to drive then the 770. Both are comfortable, but I think the comfort and build is nicer on the nighthawk, especially the cable. Overall the 770 is great but sounds more traditional, where the nighthawk is more unique and interesting sounding that some may prefer or not.
If you find that you don’t enjoy it after a couple of days, the 770 is a more traditional sounding headphone