What is your take on high efficient speakers vs. low efficient speakers?

@phusis wrote: 

The EV horns of mine both have a diffraction slot and sharp edges at the mouth area, and so may set the alarms ringing in many a horn-audiophiles’ head, but they actually sound very smooth after being properly implemented with mentioned DSP filter-actions above.

Good phrase - "alarms ringing" since that's what the sharp edges cause worry of - ringing. I get the impression from my listening that the ringing back to the throat is generally fast enough that it doesn't cause the kinds of issues that I thought - peaky, ear piercing response types of sounds, although perhaps it can if the horn is big enough. I've heard some of the really big diffraction horns bothered people in the past but it could be they just weren't well equalized. So I think I agree with you that properly equalized diffraction throat horns can still sound quite smooth and natural, although some imaging and detail might be obscured. The better high frequency dispersion may be more than worth it in many scenarios. 

Agreed this is an excellent thread! The reason for my love for high efficiency is still a bit of a mystery for me. I've been thinking a lot about directivity being a big factor - a better direct to reflected sound ratio than a typical lower efficiency speaker. This will make the speaker seem quieter in a given room but then the efficiency allows the apparent volume to come back up, so transients are clearer. Listening to good direct radiators of lower efficiency at close distance should provide a similar effect according to this logic, and to my ears it largely does, only that it scales down so the dynamic contrasts aren't as impressive as when the same effect occurs at greater distances.