In addition - these speakers, it would seem, woudl really only work with recordings that are not band-width limited to 20Kh to start with. If I'm not mistaken, aren't many cd's given a 20Kh ceiling, where there is no information above that point - and thus, no sound being produced at that point?

I understand that for some analogue recordings (tape/record) this might vary, but who listens to these media anymore with any regularity? I know that there are vinyl enthusiasts out there (and in here) who tout the benefits of the uncompressed vinyl medium (and I'm not here to dispute that - I believe that vinyl probably contains more information than cds), but if you're listening to mostly cd's or other digital media, what benefit will these add, except in the 11 or 15Kh range?