I dont listen to anything bordering on heavy metal , other than very few tracks from metallica/ac dc. I do like cymbals , guitar string to be sharp and prominent in other genres as well. When I listened to few such songs on PM8006 I did not really find the sparkle as against my Indiq Saptak, the Saptak did a much better job of presenting the details with a good amount of sparkle but without sounding bright. On the other hand the CA Azur 651a sounded a little bright to my liking. In addition the sparkle I felt the Marantz fell a little short on maintaining the pace for fast tracks (hence I perceived that it might be an issue for electronics/dubstep , but the low end boost could probably make the drops more fun to listen to on Marantz).
While it boils down to preference, personally I would prefer a fairly neutral amp (especially a power amp) as I can play around with the right DAC/ SS or tube preamp to add the warmth/details as per my preference.