Haven't heard the Quad Zs. I did ask David about what amp could drive the MBls, then someone else came in and the we both forgot about it. I am getting a very cool speaker in next week that is more amplifier friendly so perhaps it's time to call the lie detector engineer
I have heard the Quad Z mono's. They were paired with Coincident Pure Ref Extreme speakers. Front end all Allnic. This system sounded very very good. Based on the overall sound they must be very good.
If I had the funds I would ask David Berning if he could build an amp for my Innersounds that could bypass its transformer. That would be very interesting. I'm sure being a one off it would be very expensive though.