Cork, no, even that 90% setting isn't "inherently" bad, since the volume control settings are relatively meaningless with respect to how much power is actually being used. The actual loudness, as measured with an SPL meter, would give more meaningful information as to power being used, since the loudness at a given setting, such as 90%, can vary greatly depending on the strength of the input from the source material.

-----------------------------------

Enjoy the music, not the equipment.