I don't know about the 6db difference in sensitivity. 8 watts and 6db difference? I don't think so..IMHO...
That would really depend upon where those 6 watts took the efficiency down to. In the case of the Druid/Tone comparison, I'd agree, going from 101db efficiency, to 97db will not make too much of a difference listening in a room that size. If that difference were perhaps 94db vs 88 db it would make all the difference in the world for an 8 watt amplifier.
Marco