The truth on low efficiency speakers like B&W?

Yes heavy bass played loud taxes amplifier power.
The "45 watt tube amps" are being used to play normal music at normal volumes. period.
The 600 watt amps are for dudes with small dicks...
As compensation. (i guess)
The Parsound seems to be in the middle, or 'reasonable'

I can't really comment on 802s. I have 803d and 804s which I have driven with Parasound JC1s and Halo A21 amps.

Its not so much the total power, but the stability of the amp driving 3.5 ohm loads. Both the 803 and 804 (and I assume the 802) have a minimum impedance at low frequencies of 3.5 ohms (latest versions are 3 ohms). The A21 is rated for a minimum of 4 ohm loads, as is probably the 2250. At 3.5 you are stretching it. The JC1, on the other hand, is rated to drive 2 ohm loads.

To my ears, the A21 did not seem as open and relaxed as the JC1 driving the 803d. And I am not talking high SPLs where a more powerful amp would be needed. I am talking 85-90 dB where you are still under 50 Watts peak. While the efficiency of the B&W is not as good as a horn loaded driver, its not that bad either. I think mine are 88 dB at 1W, 1 meter. Newest versions are 90 dB, 1W at 1 meter.

You only need 600 W if you listen to really high SPLs. It has nothing to do with the size of your...

Got an idea what Elizabeth calls small but "normal" is up for grabs, so to speak.