I'm a dealer, but sell neither Zu nor Von Schweikert speakers. Not even sure I can spell the latter.
I'm also a longtime amateur speaker builder and shorttime speaker manufacturer. I have some experience with fullrange drivers.
In nearly every case I have found fullrange drivers to benefit from a response-shaping network of some kind, and/or rolling off the bass to allow a dedicated woofer to handle the bottom octaves, and/or augmenting the top octave or so with a supertweeter. Compared with the anomalies and distortions typically present in drivers, in my experience the minor distortions introduced by high quality capacitors, inductors, and resistors is trivial.
In my opinion the relatively un-speakerlike sound of the Zus is related to something other than freedom from capacitors, resistors, and inductors in or parallel to the signal path. I believe it is related to their unusually uniform radiation pattern through the midrange region, where most speakers have severe radiation pattern anomalies. So yes the crossoverlessness is beneficial, but I think for different reasons than are normally put forth.
That being said, I do have some reservations about the Druid and Definition; in my experience they do some things well, and some things not as well as I'd like.
Duke