+1 @atmasphere Thanks for your insightful summary. It does seem that the lowly 1.5 watt 45 tube is becoming increasingly popular.
I do have a question for you, though. When you talk about the distortion that SETs have, you also state that if they are listened to below their distortion threshold (not exactly how you put it) they are very linear. Am I correct to understand from your comments that a SET listened to at very low volumes is not distorting? That would explain my experience, which I appreciate is limited... I listen typically in the near field well below 80dB. My speakers are 94dB efficient, so I *think* I'm typically using a fraction of a watt. I know that drum hits and crescendos can require the amp to produce instantaneous peaks far above that... But I don't seem to hear much or any distortion in my system.