A representative for Audio Technica sent me their ATH-M70X for review, and I've had them for the past few days. I think that they make for a great extension of their previous M-X line.
The headphones come in a zippered case that's wrapped in a soft (I believe) faux-leather covering with the Audio Technica logo embossed in the center. Inside the case are the headphones themselves, and a zippered pouch of the same material that contains three cables, one 1.2m straight, one 3.0m straight, and one coiled which extends to 3.0m. All of these cables are terminated to a 1/8" auxiliary plug onto which a 1/4" jack can screw for use with home/higher end setups. The cable inserts into the headphones with the same locking mechanism as previous headphones in this category, with an insert, and then a twist to lock.
Now onto the headphones themselves. They feature more metal in their build than pervious members of this line, which is commendable. The headband adjusts with a delineated click, and once adjusted, they stay pretty well where the user puts them. The earcups swivel inwards such that they can be lain flat on a surface, but don't rotate vertically such that the earcups can face out, as the M50X did. Additionally, they are not foldable into themselves as the M50X could, although that hasn't been a huge issue as the case accommodates them well.
Now onto sound. These are pretty flat, to my ears, which I think is a good direction to move for Audio Technica, given the headphones' prescribed purpose is monitoring. The M50X had a considerably more V-shaped sound signature, and although these have a slight mid-bass hump, based on my listening thus far, they still lay closer to flat than previous attempts by Audio Technica.
Given that they are closed cans, the soundstage isn't anything to write home about, but the imaging and separation is precise enough that I could feasibly see these being used at the mixing station, as they fall pretty close to a flat frequency response. Also falling in line with their closed design, isolation is pretty good, and with music at a moderate to high listening level, I can hardly hear my MX Blues clicking away as I write this.
I have yet to notice any glaring faults in their sound, and have enjoyed my time with them thus far, given their use case.