I think they meant that the ZX1 is more comfortable but they sound the same or similar? They do appear to be using the same 57mm drivers. Surely they have not sourced two different 57mm drivers.
As for resembling another headphone.... I chose the ZX1 because of its unique look.
BTW, the cable is not detachable if that is important to you. Also they like some power. I have only used them at my desk so far with my desktop setup....Fubar HD dac/amp.
@HungryPanda used his Fostex dac/amp when he tried them.
I have never heard the HD800 but if the ZX1 is the same or similar in sound to the M2 then that ailexpress reviewer would have to say the same about it. Funny thing is, when I first listened to my ZX1, I was so impressed with the detail, imaging and soundstage I was hearing that I had a weird thought... wondering if this is what an HD 800 might sound like. I had not yet read those comments. Haha... that would be awesome if people are paying hundreds for for a comparible sound



ChiFi for the win!