On another note (dropping 2 more cents)....
Whoever said the Nighthawk has a narrow soundstage that doesn't extend music outside the cups has to take a step back.
Put on "Amber Rubarth - Down Home" on Tidal or Spotify, listen to it. It is a binaurally recorded song, made and mastered for headphone listening.
The violin in that song is playing 30-35cm (thats 12+ inches for you 'Muricans) from the cup on my top-right. It is RIGHT there, the violin is incredibly tangible and I feel like I can reach out and grab it with my hand.
That's another thing; with some open headphones, it is said that you can hear the music like it comes from the room you're currently in. What the Nighthawk does is it makes it sound like it comes from A room, specifically the room/space in which the song was recorded, never the room where you are (IMO).
The Nighthawk is said to sound like speakers with its frontlike imaging and we know that almost every song made is mastered for speakers.
My conclusion? The Nighthawk really tries to be truthful to the source material, and it largely succeeds.