I did the A/B test between an OTA broadcast and the cable channel to show people just how poor the cable compression really is. The majority of people could see the difference, but like you mention there's always at least one person claiming to not see it. These are definitely not someone to hire as a QC/QA team member!

Idk why they have to make it so weird. My 2.1 setup just has the sub get the full signal and the built in filter takes care of it. Id been reading about how 'perfect' the atmos to stereo conversion is... what an odd issue to run into to throw a wrench in that(or just use it as a consumer). I guess theatres really need that LFE channel.

We used to listen to a lot of music with Dolby ProLogic enabled even though the music clearly isn't encoded with that in mind. Since ProLogic works off of the audio phasing to decide what is sent to the rear speakers, a lot of the effects used in the music mix trigger ProLogic to send random things to the rear. It's an interesting experience. Maybe less so without the use herbal remedies too.??? Some of the call&response type lines from Beastie Boys would very clearly come from the rear, and was quite startling the first time hearing it. With 5.1 and beyond, everything is discrete tracks, so that trick no longer works. Do modern surround units even do ProLogic any more?