I wouldn't be too concerned about the differences between these two Denon models, Gene. If the Euro/Japanese unit has a different model number it means (to Denon anyway) that they consider this non-US model more fitting to the desires/requirements of the Euro/Japanese market. Both of these markets are considered to be more conservative or traditional than the US customer who always wants the "newest". To Denon Japan the thinking may be that the Euro/Japanese customer for a $6000 receiver may value a perceived "higher performance" toroid for amplification over, for instance, switching for four rooms. In other words the feature set may be quite different indeed. It is, after all, a different model number.
Note also that there seems to be alot of room left in the chassis forward of the toroid. No airbox to cool the internal parts which may indicate that it was a heck of a lot more difficult for Denon to meet UL approval (US only). Another reason for the more compact-transformers-with-air box that the US is getting. At these kinds of prices (for a receiver) you will sometimes see these quite different model derivatives.
To get back to the subject of this thread, Chris K. from Audyssey told me during our interview that the US 5805 might not even come with a microphone. The thinking of Denon might perhaps be that they were weighing the possibillity of having the 5805 sold, installed and calibrated only by professionals (who would have an approved microphone on hand). The implication being that this unit's small production numbers be targeted exactly to those who could set-up this complex piece of gear most effectively. Obviously the odds for "pilot error" on this extremely versatile receiver goes way up if it is sold to untrained consumers versus professionals who have learned to use and install the gear. And no manufacturer wants to place his statement piece in that type of position.
Like you stated, Gene, we'll find out more at CES!
