These are the measurements I got from my friends B & W 800 D3s.
The blue trace is on axis, and the black one out to 90 degrees, where there is a suck out at 1.8 KHz.
Waterfall plot.
Impedance and phase angles.
Any respectable amplifier should be able to drive those speakers.
As you would expect from those measurements the speakers sound excellent. So I would have to put them in the reference class. They are a significant improvement from the precious 800 line. My only criticism is that they seem to sound a little distressed at high power in the massive forte's. My speakers seem smoother and more relaxed when the going gets really rough.