I've got the latest Topaz. I spent several months earlier this year researching and auditioning before buying the Topaz. I also visted with Roger Hebert and heard it in his system with the Coincidents and Tannoy Churchills.I think he now has the bigger Zu's on hand.
I've got the Berning ZH270 on hand along with Futterman OTLs and various others including the Atmasphere M60's.
Front end is the Aesthetix Io Signature w/vc + 2 supplies + Koetsu RSP.
All going through refurbed ESLs or USA monitors.
Unfortunately, I don't think that you'll get much response on the Topaz as there are not many out there. Apparantly, there is a current review in the Canadian mag "The Inner Ear"... I have not seen it yet...but I have listened to the Topaz in The Innner Ear's "studio".
I would have liked to hear from others aswell on the Topaz but had to go to great lengths to hear it in other's systems before I bought.
It's built like a tank with brute force power supplies rather than say, the Berning's cutting edge elegance and leading edge innovation. Speaker match is everthing. It's nothing like any other SET. No soft tubby bass and it's fully extended. It hangs images in air like no other I've heard including some multi mega $$ amps. Hebert's working on a statement product that will be loosely based on the Topaz and will cost many more times the Topaz's price. I think if were distributed through normal channels the current Topaz would cost 50-100% more.
Good Luck