The Sound of Speaker.

@OP,
When I was a student, with limited funds, I bought inexpensive drivers and built my own speaker cabinets. I learned about the very basic stuff to make speakers which allowed me to use an inexpensive receiver and a turntable to play through the pair of DIY bookshelf speakers. 

In the meantime, I look at reviews and tests, and go listen, in search of the 'perfect' speaker. As a person trained in the sciences and engineering, well as in music, a speaker must test well - not just the linear tests, but the non-linear tests too. Then I listen to speakers and it must sound real, enough to convince me that I am hearing what I expect to be real without having to concentrate to hear it. The speakers should also be listenable over many hours without fatigue. Too many speakers fail this last test, while giving a good initial impression.

It doesn't matter what technology is used to reproduce the music - horns, panels, cones/domes, ribbons, AMT, etc. If the final sound waveform is a facsimile of the input waveform, then that's the best you can expect from the designer. If testing shows this is so, and the sound tells me it sounds real, then I'd buy that speaker (if I can afford it).

Also, consider whether you will listen to the speakers for two-channel music, or will you also use it in a home-theater 5.1-, 7.1-, or more channels arrangement. If both, that could limit your choices in which speaker design you use. Good luck in your search.

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.