(I'm posting this in the Pure Cinema mode thread as well. Apologies in advance for the duplicate.)
I have been emailing back and forth with Pioneer customer service for several days trying to get to the bottom of whether or not the 5080HD will automatically engage 72 Hz refresh rate when Pure Cinema is Off and the signal is native 1080p/24.
Today I received what I hope we can all consider the definitive answer:
I researched your question further, because, yes, the manual is ambiguous about exactly what occurs when Pure Cinema mode is set to off.
The answer I received was that Pure Cinema mode self-engages when this 1080p/24Hz signal is detected. So even though you haven't selected it manually, circuitry activates to turn it on automatically, kind of behind the scenes or in the background.
Of course, this still doesn't explain why Pure Cinema Off is noticeably brighter than Pure Cinema Advance, all other variables being equal. My guess is that Pure Cinema Off simply engages 72 Hz and 3:3 pulldown, while Pure Cinema Advance performs additional processing.
Please note that my question was specifically about sending a native 1080p/24 signal, not film-based 1080i content, to the 5080HD.