The short answer to whether it feels softer than what I prefer with hard rock would be....
NO. In fact think that the transient attack/speed of the VC is better than that of the HiFiMAN HE-1000 (which I still think is awesome), as I've detailed
here. If you are still considering a different amplifier, then I would very strongly recommend the MicroZOTL 2 by
Linear Tube Audio. The sound is fantastic. Many people have said that it combines tube smoothness with solid state detail. I agree. To me the sound approaches perfection, especially for a headphone.