Having mixed with both, I can say the Nighthawk didn't exaggerate or alter how the recordings sounds but the Ether did. The Nighthawk also has much less distortion, and even lower distortion than the already super low Elear. The Nighthawk was also more resolving than the Ether and Ether C bringing out those micro details better where as the Ether blurs those finer details. The thing with the Nighthawk is the cups do have a reverb so they can sound a little different in that aspect but the actual frequency response is fairly balanced on the NH.
The Ether drops off too quick in the bass and also lacked bass detail and definition and this is from a Gumby + every amp I tried them with like the Lyr, mol2. If the Flow can fix that to a degree and was cheaper It would be a contender for sure. The latest measurements from Tyll didn't look good in terms of bass extension.
I still think the Alpha dog is the most resolving headphone that has come out of dans lab.
Maybe the Ethers seem lacking in bass detail because the Nighthawks are are dark headphones with boosted bass-midbass.
Same as Alpha Dogs which I had to sell almost instantly lol Way bassy and lacking presence with weird soundstage. (The speed of them I think though is out of this world) um anyway I think both Ethers are more competent than the nighthawks in overall neutrality and detail, but they are a tad bass light.