I don't often see power specified as FTC power, so power specification can be very flexible (often much worse). I found in the specification of Icepower module continuous power (40W) and FTC rated power for 0-3kHz (150W).
So we have continuous, FTC and momentary powers and anything in-between. Perhaps for linear power supply amps weight can be a better specification than power?
As for the listening distance - Benchmark claims that in average room distance doesn't play role. 6dB loss for double distance applies to open space only.
Rule 13: In a home environment, the SPL at the listening position is about the same as the 1m response of the speaker in an anechoic chamber.
If a speaker has a measured output of 90 dB SPL at 1 meter when fed with one watt, you can expect about 90 dB SPL at your listening position when driving your speaker with one watt. Room reflections supplement the output of the speakers and compensate for the fact that you are more than 1 meter from your speakers. If you are outdoors, this rule does not apply. But, in a typical home listening room, the rule works reasonably well for a quick approximation.