I don't see any debate on that point though. Or did I miss something? In this review, Amir's findings showed the pre outs were not affected, at least not in a bad and visible way, if someone says "it affects..", I don't know what they meant and what supporting evidence they have. It is quite possible I missed some posts in this 21 page thread lol..
The following graph is SINAD versus Pre outs under no speaker load condition, that's exactly the condition you stated in your post, is that correct?
Based on this, I would be very happy to use the PioneerLX505 as preamp processor.