>>Is that all? Those measurements suggest way more issues than that...<<
Druid, at then $3600, was not as linear as the later $11,000 Definition, Zu's second speaker. But then no one expected it to be. It has a somewhat warmer overall tone than Definition, Superfly and Omen Def. But it was accurate as loudspeakers go, and smooth rather than ragged in its response. The lack of a floor under the partial Griewe loading scheme affects the full range driver's performance well into the midrange.
Most speakers yield a test graph more ragged than they sound, BTW.
Phil