I have a set of KEF speakers that have an interesting concept... the drivers are all nested inside each other, one on top of the other. They say that having the sound source focused like that reduces phase error between drivers. It's an interesting theory and the speakers certainly sound fantastic, but I do see limitations that might not make it the best way to go in some circumstances.
It's human nature to want to define things as "best"... best technology, best design, best brand... But there are always trade offs and compromises, and defining what "best" means requires specifying the application, because best in one circumstance may not be best in another. The way to do that is to point out what works well with a particular application of a design, and listen to information about the situations when it may not work as well. Then you can decide whether something really is best for you.
Or you can just do it the easy way and assume that if a certain design actually was best, everyone would be using that design. I'd say KEF's unique design probably falls into that category. But it works for rear channel speakers because they have very wide and accurate dispersion and can mesh across a wide distance.