Tvad,
Speaking of missing threads...is there any YOU have missed in the last 6 mos?? You are one amazing dude! ;-)
Jack,
My experience as a former 6381 and 6371 owner mimics Mondo's to some extent. The Ushers are very good indeed. Iv'e had a lot of nice things to say in the threads about the sound, design and just great looks of the speakers..But, after hearing the Druids at a friends home, and after much pleading with him to sell me his pair after he upgraded to the Defs..I can say that they are in another league in many ways...Especially because I listen in the quasi-near field or about 9-10 ft from the speaks,..The Druids are more coherent and seamless sounding..much better for my particular room..but, more than that, Their tone and texture is more realist and purer sounding. Bass is tighter by far, although not as powerful as the Ushers. I dont think the Ushers bass is anywhere near as accurate as the Zu, and that matters very much with respect to tonal coherence, and not getting in the way of the rest of the sound.
Like Mondonitro mentions, the single driver presentation is something that makes you aware of other speakers sounding more hi-fi, rather than real. The wide bandwith coherence is very pure and allows you to get much closer to the recording.The Zu's sound taking on a darker, more fleshy tone, over the Ushers laid back, but lighter weight upper ranges. Dynamically, its no comparison really...What the Ushers compressed when the music gets loud, the Druids just pass right through with ease..a much better free breathing and transparent quality to the sound. Its funny, I really loved the Ushers and thought very highly of them (still do),,,but, the Zu's just do it all better, cleaner,more resolution, less grain, less compression, tighter, more coherent bass..deeper soundstage, more precise imagaing, and better texture.Im sure pairing them with a low power 845 Triode amp is instrumental to that type of sound.
I cant even think about going back to a multi-driver, cross-over type speaker, or the limited dynamics Electrostat type planar after living with the Druids now. Not because they wont sound as good..but they dont sound as good in my room, to my ears. and Ive had way too many systems in and out of the room over the years to know that. I think I'd choose a high quality mini monitor in my room if I had not heard the Zu's. Nothing like a Klipsch as you mentioned tonally speaking. They share only the fact that they are both high sensitivity speakers.
Anyway, that's all my opinion of the differences from the Druids and Ushers as you asked for. Hope this little bit of non-wisdom helps.