No, I've never listened to an SET, but I would like to. Theoretically, I think it should be the best; especially the 300B SET.
I hate to use "abstract" words and at the same time speak in scientific terms, but I have no alternative in this case. My scientific theory coincides with the word "soul". I listen for the "soul" of the music. This is something that's different than the "sound" of the gear.