The AKG Q701 were not much more than a recoloured K701.
Measurement variances can fall under manufacturing differences over time, as there have been so many re-releases of the K701, 702, Q701, K712, K7xx, etc (I've owned or heard roughly six different pairs now). One could ostensibly make an argument that the Q701 was tuned to have slightly higher bass distortion thus making it seem fuller in that region.