I wouldn't fancy a big black slab with wires coming out of it on my desk. I hate wires.
As for another drawback of this formfactor; the end is too thick. Therefore the keyboard's angle gives me pain in the wrist. The old 8 bitters and the A500/600/1200 have this drawback aswell. But they get away with it because they are old computers ;-).
I've never seen one for real either.