Not sure if this has been covered here but its important to realize efficient does not mean easy load. Not easy load means not just any amp will do to get the best performance possible.
Nothing wrong with any of the speakers mentioned as long as proper amp matching is done.
I have gone through similar gyrations considering "more efficient" speakers. But more efficient just means louder not better. For better, you want speakers that are easy to drive with any amp, and that would be Fritz speakers. There may be others but those are ones I know, have heard and can vouch for the fact that they will perform well and go reasonably loud even with most any amp. I heard them with a flea powered tube amp at Capital Audiofest a few years back and was won over.
Having said that, teh best high efficiency speaker sound I recall ever hearing was with a pair of large custom goto horns at the very first ever Capital Audiofest years back. Others I have not heard that I would love to be able to audition but have very low WAF are Jadis Eurythmie and Avantgarde. I’m sure there are others. I tend to always like Klipsch Heritage speakers when I hear those and would consider those to be very good relative values worth consideration. Volti as well. Have heard and liked Spatial as well but not sure if those qualify as truly high efficiency.