btw a lot of the output in so called high efficiency designs is trash ( distortion ).... which the efficiency spec takes no note of.....
Maybe true, but our hearts and ears buy speakers, not test gear, so it is worth listening with your geek off.
But I do think that listening to Vandersteens as exemplars of low order crossovers is a good idea if that is your question. Of course, you can also listen to full-range (i.e. single driver) zero crossover speakers to see if they float your boat in terms of dynamics.
Or for something truly different, build the Seas A26 kit:
https://www.madisoundspeakerstore.com/2-way-speaker-kits/seas-a26-10-2-way-kit-pair-based-on-the-cla...
In terms of crossover slopes, it doesn't get much simpler than this.
Best,
E