I downloaded the English version of the manual for the RX-Z7 and the notes on page 46 concern me.
They state:
When you play back DTS 96/24 sources with any sound field program, this unit applies the selected program without activating the DTS 96/24 decoder.
Huh?
Sampling frequencies higher than 48 kHz are sampled down to 48 kHz or lower and then the sound fields are applied.
Seems like interesting behavior for a flagship line receiver. I have a query in to Yamaha on this and have not yet gotten anything more than we will get back to you on it - though that response came from a real person.
I have to wonder what else besides video processing is going to distinguish this receiver over the 3900 to make it worth the extra cost.
I own an RX-V2500 now, and I was initially very excited about the RX-Z7; however, now I think I will wait for reviews before I make a final decision to purchase on.