I just got these a couple of days ago. Early impressions: treble is just a little hot, but not uncomfortably so. Bass is extremely tight and very well controlled, but just slightly lacking in sub-bass.
Vocals from artists with a lot of "texture" in their voice (think J. Roddy Walston) sound just amazing. Smoother vocalists (think Elizabeth Fraser with Massive Attack) are crisp and clear.
The Sound stage really, really depends on the mix of the track. Older stereo recordings Like Miles Davis and John Coltrane sound almost too separated into left and right channels, but present a very wide soundstage. More modern recordings tighten up the soundstage, but sound more coherent.
These are pretty comfortable, love the ear cups, clamping force is just a tad light, which causes the top pad to sit heavy on the top of my head, not my favorite.
Setup is Tidal Hi-res and MQA from TIDAL WIN10 app on a Surface Pro with all software decoding off (internal DAC bypassed) -> Grace SDAC->Dark Voice 336SE OTL-> DT990 premium