Just reporting what's published, Ethannnn...
Of course, a speaker's resistance plays a part, too.
My limited experience at home with a Bryston 4B SST, Bryston 14B SST and VAC Phi 110/110 and VS VR4 Gen III HSE speakers (89dB/1 watt/1 meter, 6 ohm nominal load, dipping to 3 ohms @ 20hz) is that the 100wpc VAC drives the VR4s as well as the 600wpc Bryston 14B SST.
Of course, a speaker's resistance plays a part, too.
My limited experience at home with a Bryston 4B SST, Bryston 14B SST and VAC Phi 110/110 and VS VR4 Gen III HSE speakers (89dB/1 watt/1 meter, 6 ohm nominal load, dipping to 3 ohms @ 20hz) is that the 100wpc VAC drives the VR4s as well as the 600wpc Bryston 14B SST.