I agree with the statement disputing the claim, both "ProAcs and Von Schweikerts, for example, will do full-scale concert dynamics in a 10 x 20 room, with overhead to spare, on a typical 2A3 amp." To me, "full scale concert dynamics" range from 100 - 110+ dB. A 5 watt amp, powering even a flat 8 ohm, 93 dB sensitive speaker, would not be able to reach those levels "with room to spare". I am love with a certain 3.6 watt 2A3(and will hopefully buy one). As great as this amp is, with the dynamic speakers I have listened to it with(more benign loads than any Von Schweikert), it never had this kind of drive. Yes, it is ADEQUATE(and a WONDERFUL) amp, but you are making a similar analogy to a car being able to pull a freight train. Ain't going to happen. Let's rejoice in the beauty of a great 2A3(and its superior sound compared to a 300B), but we need to remain realistic.