Coaxials - Reality vs. Experience?

which you are calling "narrow vertical dispersion" and as a "benefit" It is not a benefit, but a downside.

I absolutely disagree.  In a brief reading of articles online you'll see that the horizontal dispersion control of D'Appolitos is in fact a good thing, as it is for tall ESL's.

Generally speaking, the more controlled dispersion of a speaker the less acoustic treatments a room will require. 

Further, you literally can't have a point source if you are deliberately changing the dispersion on one or the other axis.

I came full circle back to kef and i'm not sure if it's because of my familiarity with the house sound or because they just due midrange better. I had the r105/3 and consistently listened at 104db peaks and the louder they played the more realistic they sounded. I was always let down by the bass which measured good in room but just didn't sound full bodied. I would say the benefits of the kef design is fairly easy placement to get most of what the speakers are capable of, most will be under powered, but many speakers that design for a flat in room response sound bass shy and take time to adjust to. Kef Blades have ironed out the midrange driver reflections making for a softer and more detailed treble play back than earlier designs and bass has been addressed.

I had Tannoy 10" Red's and Altec 604-8G's in refrigerators.  I couldn't cotton to either.  Then I landed a pair of JBL Hartsfields 15 years ago.  They are my forever speakers.  I love the 375 compression driver through a horn!  I also love my Quad 57's and LS3/5a's~

One sound quality I rarely see mentioned is how a speaker sounds all around the room. While the "listening" position is important, I also demand that speakers sound good as I walk around the room, and also around the house. I’ve had multi-way speakers whose sound falls apart as soon as you stand up.

My 15" Tannoy’s fill the room, and sound natural all around the room, and while I’m working in the kitchen. This is very important to me. I also use an 8" Tannoy driver as a center channel (in a DIY cab). It makes an ideal center, with no off-axis "phaseyness". No my Tannoys are not perfect, but this is a quality that they excel at, over non-concentric speakers.

Hello everybody, please help me with a dumb question that I do not know the answer to.

closenplay stated, 

"To add clarity, concentric is a subset of coaxial. In other words, all concentric drivers are coaxial but not all coaxial drivers are concentric. @erik_squires Pardon the presumption; you are probably referencing most designs intended for the hifi home user, of which most (if not all) are concentric."

I know what "coaxial" means but how are you defining "concentric"? Are you suggesting that two coaxial drivers (i.e. their voice coils) may me mounted  at an angle to each other? That they are centered but not perpendicular? Or? 

sincerely

herb