The MHP1000 was on display in room 8030 in addition to two loudspeaker setups, so getting a listen seemed bizarre. I ended up in the room alone at one point and got a listen.
My impression: these are full sounding bass heavy phones, somewhat reminiscent of the Fidelio X1 below 500hz, but without the low-bass rolloff. I would guess that 50hz was 6 or so dB above 500hz. Distortion in this area is low enough to keep it clean sounding however, and the experience was not unpleasant. With my content, 1khz+ had overall balance with everything (typical downshelf). Presence was there and not excessive. The 4-9khz didn't seem harsh or peaky, but didn't seem particularly clean or smooth either. The overall impression is a slight U shape.
The McIntosh MHP1000 sounds like a good dynamic closed headphone balanced for the impression of luxury. As a closed headphone, the MHP1000 left me thinking it was better than the Blue Microphone Mo-Fi and the Sony Z7, but just different from the Audeze XC and probably just as flawed in a different way.