Single driver vs traditional 3 way loudspeakers

FR - Full Range (i.e. 1 driver to rule them all)

MTM - Mid/Twetter/Mid, kind of but not necessarily synonymous with a D'Appolito alignment.

They have narrow vertical dispersion, but also thanks to the dual drivers, less IM distortion, and if crossed to a good woofer, even less.

I wouldn't say they are the easiest to get right, I've seen some famous makers recently make questionable choices.  Hahahaha. :)

God forbid somebody want to live in that midrange for awhile. Have You ever spent real time there? 

I'm just breaking in a pair of Omega Junior Alnico singe drivers and when well-positioned, are a dream come true for experiencing the clarity and spaciousness of imaging, the detail, the direct line to the studio/venue/mixing board sound.  

I love my Klipsch forte iii for a lot of things, but I'm keeping these omegas around for a while and maybe pad the experience with some small subs.

Not worth your energy hating single driver speakers if well done. 

OP, I recommend auditioning a pair of Cube Nenuphar’s or Nenuphar Mini’s, they are quite a bit better than other full range speakers imo and better than any other speaker I’ve heard with crossovers, including speakers costing considerably more. They need to be used within an appropriate system of course to hear them at their best and I suggest reading David’s thread on AG about the Nenuphar’s to get more information.

I have a pair of vintage Tannoy Gold IIILZG 10", recapped they are beautiful and I don't miss bass with the right source and setup. I also have a pair of Audio Nirvana Classic 10" (50hz to 20K)
(https://commonsenseaudio.com/ ) being built into their own floor standing cabs. I run a single end class A 6wpc tube amp,so I need the sensitivity. With 2 ways, unless you have good power and a high quality tweeter that isn't harsh you loose a lot of detail. To me the full range sounds natural and detailed, good air and sweet highs and decent bass with the right  setup. Their more prone to placement but I much prefer them over 2 way. If you haven't had much experience with them I highly recommend giving them a try! 

Back in the sixties and possibly into the mid seventies, JBL and Stephens-Trusonic produced what they called extended range or full range drivers.  Both used an aluminum dust cap for the mids and some of the lower highs.  For optimum performance, they were designed to mate with a tweeter, but on their own they still sounded very good.  No x-overs, not even a capacitor.  I believe there were 8,12,and 15 inch versions.  They come up on E-bay occasionally, but the aluminum dust caps are often dented.  I once had a pair of the Stephens 8 inch variant, and it was a very well made speaker.