The Sound of Speaker.

Nothing wrong with a good horn speaker. It is a little more difficult to get them perfectly smooth but they do limit dispersion which improves room interaction. I would use them with a BBC curve because they tend to have an edge in the upper midrange. 
As far as ESLs are concerned  you have to audition those that are as tall as the room, 8 or 9 feet. These are significantly more powerful than 5 or 6 foot tall speakers and in most instances smoother than horns with superior imaging, no crossovers. They are not as efficient so they do require more power, the price of admission. 

"...They use to fill the base with sand and tune that Watson..."

I think you meant to say Watkins? 

I never consider myself as an expert about speaker, I just have experienced owning some Magnepan, Dahlquist, AR9, JBL250, Martin Logan, KEF, Mission, Rega, Tannoy etc...
I am still using Rega Ela in my Reading-room and there are 5 set of Stereo system in my BR, Garage, LR, RR and DR.
I don't have nor I wanna  have thick-skin just to be able to share a hobby that I love, so I guess I was in the wrong place.
I will sign-out and maybe I could find a different forum where I can share this hobby and where some members not trying to look good by insulting each other.
Good luck all and Good-bye!.
       

"...to use the word "Prejudice" seems too harsh I think..."

Yes, perhaps it was but I try to tell people to keep an open mind and discard preconceived notions because there is fabulous gear in every design configuration. Never discount gear due to the design, listen first. We all have our favorites but I'm willing to try or hear as many designs as possible. Some products work and some don't but they deserve a listen first. 

Prejudice?
Sounds like aprejudice to me.
Happy that you found what you like.
If you are there, an open mind won't improve your life any.