Single driver speakers. Are they worth considering ?

I would love to hear the Shindo Lafite.  I like the Latour (two-way field coil Shindo system).  I really like field coil drivers--they sound very dynamic and "alive."

While I would be totally satisfied with a Charney full range system, and perhaps the Voxativ back loaded full range system, I also think iopscrl (above) is correct that you get much of the advantages of such drivers while ameliorating the limitations of trying to deliver all the sound from one driver by using such drivers to cover a wide midrange.  I have heard the Jensen M-10 (13" field coil) with a tweeter, and the GIP Laboratory 4165 (12" field coil) with a tweeter to deliver the kind of dynamics and clarity that full range systems are known for, while being much smoother sounding and extended at frequency extremes.  

I have heard Western Electric 755 drivers used in single driver systems and in systems with a tweeter on top (only crossover is a first order high pass to the tweeter, the 755 runs full range) and much prefer having a tweeter in the system.  I think systems using the Western Electric 756 and 728 with tweeters are even better.

German Physiks has perfected the Ohm Walsh-style driver that handles 190Hz and up. They’re simply magical in a way that none of the multi driver speakers eg GE Tritons can do. 

The main issue full range driver is suck out upper bass and lower mids so you listen much more thinner sound than good 3 way LS, that reason that majority audio guys hate SD . The Perfect Single Driver that can work alone with no issues unfortunately does not exist.