Very interesting.
Also, I'd like to share another observation with the Heresy III. When they are off the floor, the mids and highs are fantasting, but the lows are a little lean. When I add 2-3db at 150Hz on the amp, the lows totally come back and the strange thing is that I can hear clearly down to around 20-30 Hz, which doesn't happen without this adjustment. Also the bass gets very clear and warm (I think that's partially because of the Rega CD player too). On the contrary, when they are on the floor, there's too much bass, but not as warm and clear. May be there is a height and tilt where the sound will be balanced but I haven't been able to play that much to find it.