Single driver vs traditional 3 way loudspeakers

What you prefer , single driver , no crossover, full   range  loudspeakers powered by low power SAT  or traditional 2-3 way design ?
can you compare Charney with Tektone or Volti ?

I have never listened to Tektons but Volti yes at the 2015 NY show. Volti was exhibiting a few rooms down and across the hall from Charney. Volti had his large horns and bass unit, the name escapes me at the moment. All electronics were Vinnie Rossi’s Lio preamp and 200w amp with what I think was a Palmer TT.  We listened to ZZ Top LaGrange at loud and clear volumes felt like I was riding a Harley. I felt the sound in my bones but wasn’t drawn into the record like the Charney Concerto does. Sounded somewhat flat in comparison and uninvolving. The Voltis rocked out and delivered clean clear sound no question but lacked the X factor for me. Just my opinion...
Only a preliminary assessment can be conducted based on one comparison of two different systems. If the speakers are similar enough in terms of efficiency and impedance curve, one could theoretically swap them and have the preference shift to the other speaker. That is how difficult it is to draw a firm conclusion in regard to assessing two different speakers at a show. Still, it's better than never hearing.

The big draw, as should be expected, of a single driver speaker is coherence and very tight center imaging. Full range speakers do this exceptionally well as a lot. Expecting them to do other things as well as other technologies in speakers is unrealistic. They may, or they may not. 
Full range are often lauded for such wonderful midrange, but I find that one can get that with nearly any genre of speaker - if you work at it and optimize the system. It's easy to say the midrange is all that when there is no bass worth commenting because a swath of frequencies went bye-bye. 

Full range better than other technologies? No, not at all. It's just garnishing a different set of performance highlights in keeping with the design. It's to be expected. Switch to another genre of speaker and hear things that a full range can't touch. For example, a very well built multi-way can be superior in terms of resolution/definition. 

It's all part of the game, as with low/high power.