Albert, how could I know that a new rear-mounted speaker-variety selector switch and new wide-band transformer would be considered "options" and not evolutions? My apologies. I did not listen to the Wolcotts for 250 hours as you suggest and that could explain everything. It often does. Nevertheless, I found the Jadis JA200, JA100(especially), JA80 and Audio Valve Baldur mono blocs to sound significantly better than the Wolcotts on Wilson Watt/Puppy 6s or Vandersteen 5s. Their superior sound was completely comensurate with their superior cost. I found that the ARC VT200(used)and the Audio Valve Challenger 140 equaled the Wolcott in sound and cost. I can easily understand how you would prefer the Wolcott to the Atmasphere, VTL or Viva amps. I haven't heard the GT400 but I trust your judgement here implicitly. Please don't misunderstand - I LIKE the Wolcotts. However, I am wary of any product that bills itself as "breakthrough". And, I feel there are several "conventional" amps similarly priced that just might sound better even without any options, revisions, design changes or evolution.