JLM,
Perhaps I have created some confusion with my post because I'm *assuming* that there is a middle ground between the very-highly-sensitive speaker (and low-watt SET amp) and the typical, say, 88 db 8 ohm speaker (and the amps which will drive it).
This (ostensible) middle ground has more sensitive speakers -- not absurdly sensitive (100 db) but not down around 88 db, either. This is the range of about 92-97 db where very modest amps could drive it with a lot of dynamics but not be introducing the kinds of distortions you're indicating are the cost of highly sensitive speaker designs. I imagine such a middle ground because I read about, say, Tekton or Omega or Devore speakers with Raven or Schiit or First Watt amps. Etc.
But maybe it's the case that once one goes above a certain sensitivity (say 92db) they're all highly sensitive and distorting in the way you describe? If that's true, then I can more easily see why my proposal (for a Salk speaker that is above its usual sensitivities) is misplaced.