As I've read, I can say that this is not for you. AFAIK you want a headphone that is detailed, accurate, without any coloration & other plus points for a monitoring headphone (that can be used as primary headphone to listen to black/doom metal & its sub genres (I like your taste, extreme and dark)) and IMO W1000X is far from your desired qualities. Read for yourself:
but Audio Technica ATH-A1000X seems to be something for you. I'm not sure though. Let experts say. However some say they have the same problems that most of open Audio-Technica headphones have.
Yeah, you are right. It seems W1000x is not suitable for me. But I couldn't find much info about ATH-A1000X & Koss ESP-950.