I've been unfaithful with an SET amp.

I bought this Chinese SET just for the fun of it,received it put in NOS's and the rest is history. I still like my neutral Joule Electra Stargates, and listen to the Stargates 85% of the time. But the SET has a tug on me the whole time. I take it out and play it when I'm alone or just feeling more emotional, the involvement is simply incredible, hard to walk away from , with of course ,the right music and recordings. A very intoxicating and habit forming experience indeed!
There is a truth in your words: In my opinion you cannot listen to SET for a long time -- annoying! It's very music specific if you want to listen to voice or some single instrument... Otherwise beefy push-pull will honestly play any kind of music and drive a "heavy" speakers.
What does SET stand for anayway?
"Sentimental Every Time".

Although some people claim it means Single Ended Triode.
Low power SET amps are mean to use with very efficient speakers. Pair it with the wrong kind of speakers will lost all its "annoying" magic. Be open-minded people...........
...you mean with 100dB efficient ones? I believe these horns are lifeless and have a black-n-white color of sounding.
Need at least 90dB. The B&W old P Series work well.