Most high-quality loudspeakers are 4-Ohms

Mapman, actually you've gone too far in the opposite direction. Most ss amps aren't at their best into 16 Ohms. Remember that a ss amps that doubles down from 8 Ohms also halves up from 8 Ohms. The safe bet for ultimate amp compatbility would probably be around 8 Ohms, and perhaps 6 Ohms for mass market amps.

Like I use mass market drivers.

Unsound you said [I suspect that many speakers that are designed to be more effecient are in fact not so due to inherently superior drivers or other design parameters but, done so that they can better accomodate particular amplifiers and that course of action might just very well compromise the ability of the very speakers themsleves] You can have this opinion all you like but if you understood even a wee bit about transducer or loudspeaker design you would understand how wrong you are.

JohnK, not that I thought you used mass market drivers, but how the heck would I know what you used. Are you a speaker manufacturer? Another speaker manufacturer who on this very thread has posted that what I suggested is part of his decision making. Is he so wrong too?

"Most ss amps aren't at their best into 16 Ohms. "

I'm operating under the assumption that a higher damping factor is in of itself a good thing, all other design factors aside.

Of course we all know what happens when one assumes.....

I suspect different amps will still sound different into 16 ohms and not play as loud, however there is less downside potential along with this as well, if not optimally matched, hence 16 ohms is safer, as I indicated, but not necessarily a lock alone for optimal performance.