Regarding speed and rythm, when I listened to “I love being here” from Diana Krall “Live in Paris”and the owl made me tap my feet, while the hawks made me lean back and relax. The treble can even be a little sharp at times. Mids and highs are clearer, it feels like all the frequencies have more energy. Bass it drier and punchier and has more power in the lower registers. The Owl still feels a bit more foreward, more “in your face” but it is also faster, more rythmic, and more balanced. The Hawk has this super relaxed feeling, and at times feels a little more natural. I find that it really depends on the music which ones I prefer. Also the soundstage has opened up a lot and is much closer to the one of the Hawks now. It is far smoother and more liquid than in the beginning, very close to the Hawks now.

New out of the box the NO was much more 'into your face' than the (burned in) NH, and the soundstage was much more compressed.

The NO has about 50h burn in time so far and changed a lot during that time. The Hawk was a demo unit, so I assume it’s fully burned in. I recently bought both the Nighthawk (original) and Nightowl.

Audioquest nightowl sound leakage