Here is an update in case anybody is still interested...
The auto-MCACC on the new
VSX-D912 receiver does
not include the equalization feature that the Elite models have. For me, this makes it basically useless; one can do the basic balance/delay calibration just fine with a RadioShack SPL meter and a measuring tape. The per-channel equalization is
the feature that makes the MCACC unique and potentially valuable. After all, you get what you pay for...
Also, I just got their response to an inquiry about the 4-ohm shutdown issue that I sent directly to Pioneer's Tokyo headquarters. They
flatly deny that the "issue" exists, saying that the specs clearly state that speakers rated 6-16 ohm should be used with the Elite receivers, and these models are designed accordingly. They also deny that they have done or will do any update, repair or modifications to the receiver to accommodate 4-ohm loads upon a customer's request. They said this even though I phrased my inquiry sound like the 4-ohm issue is the make-or-break factor for my purchase decisions in the very near future. Incidentally, they were prompt and appropriately polite in answering my questions.
So, I guess I have to conclude that Pioneer, for whatever reasons, does not want to go public or official on this issue; they even took the risk of losing one potential buyer in denying the issue. On the other hand, judging from recent posts in various forums, Pioneer does seem to "fix" it on case-by-case basis upon customer requests, apparently regarding the fix as the normal repair of an individual malfunctioning unit under warranty.
Just FYI...
Cheers!