Single driver speakers. Are they worth considering ?

@ kenjit1 " KEF likes to do single driver point source speakers. It depends what you want. Single drivers have less highs but perfect dispersion. A 3way speaker has clearer sound but horrible dispersion.

Nonsense.

1. KEF offers zero "single driver" products. At minimum KEF hi-fi speaker systems are coaxial, with two distinct though concentrically mounted drivers.
2. There are numerous products on the market with excellent dispersion properties. Is it your contention that Magico's published assertion that the M3 has "ultra-wide dispersion characteristics" and ultra-low distortion measurements" is false advertising or exaggeration? 
3. Allow me to disabuse you of the notion that single drivers exhibit better dispersion properties than a proper multi-driver system incorporating a high grade tweeter: https://www.soundandvision.com/content/dispersion-show-and-tell 

Currently running Fostex Fe208ESigma in free air with a NAD D3020 and sub. Also running Audio Nirvana 8" alnicos in free air, with a class D icepower ASX125 and sub. I listen at around 58-60db. Krall, Jones, Fagen, Lofgren, Davis, Clapton and similar music. Sold a Primare I30 to finance most of the above pieces. Best decision so far on my personal music journey. Cheers, gotta love this hobby

IMHO single drivers suck.

It’s all about where you’re willing to compromise. I have a diy 6.5-inch ported bookshelf speaker that I think sounds great — for what it is. The mid-range is just very sweet and the highs are good. But I added a subwoofer soon after. Looking at my speaker measurement w/o the sub, I’ve got a nice 100Hz to about 8 kHz spectrum. That used drivers costing $100 each, so not cheap-o but not fancy either, with neodymium magnet and a cast basket, so good construction. And I tuned them pretty carefully with acoustic stuffing and port size. Put on girl-with-a-guitar music, or “unplugged” Clapton or Nils Lofgren, or moderate-level jazz or combo, or chamber music or piano solo, and they do great, a real pure sound. And think about it — that’s a lot of great music! It’s probably about the time domain and point source and other stuff I’m not competent to address. Ask Atmasphere. And they were 95 dB sensitivity for the 15-watt class A amps, so a good team. But not as a do-it-all speaker, I’d say.

Feel the most famous single driver speakers would be the Bose 901. Yes they had multiple drivers but all to form a single driver in basic delivery. What was the quote “ no highs no lows must be Bose”. I did and still have a pair. Need an amp that had a power supply that could double as an arc welder to drive them properly. Sansui 9090 Them run through a eq to shape the sound by bending the wave form to an extreme level. Yes set up right and playing loud to an over served crowd they sounded good. Set up with a quality system in a listing room you keep struggling to try and hear what is in the music you know is there but you can’t hear it. I have never heard ZU speakers but they do have a good reputation and following——