DIY speakers vertical array a la "pipedreams" syst

Have any of you worked on a multi drivers vertical array type of speakers ...something that would look like a diminutive version of the http://www.nearfieldacoustics.com/The%20System.htm systems ?

What were the results?

i have a suddent interest in knowing why so many people
prefer this kind of setup to systems of equivalent quality drivers/enclosures with less in number ...

Anyone has a good ressource for buying excellent drivers
( only the drviers ) and or reviews of such ?

i will need a 15-18" driver for my sub neway , even
if i still go with ESLs ..

But the vertical array systems attract me for a single reason, build is easy and it should cost equivalent to electrostatics ( since no need for $$$$ step up transformer
but multi drivers need to be purchased ..

I would be considering a desing of a few feet tall with a
front face of 12" to 18" maybe with an opened rear for dipole action since they can't reach the front in their resonnat frequency ...mmmm

could be something in the 3 feet tall in total
wonder how many driver i could place on that :p

what do you guys think?

then also, about the need to drive all the drivers,
will it ask for a really powerfull amplification ?
or since all the drivers are working less powerfull to
attain the equivalent sound pressure, they thus require less power ?

what do you think of nerafield acoustic theory that
having more drivers permits the drivers to be worked at lower power and drivers are more accurate at lower power?

thanks for your time,

anything will help :)