That depends on how it is used/made. There are a large number of discrete realistic 5.1 recordings that are derived from real acoustic events recorded in real time. More common (even typical) of classical recordings but there are many non-classical ones as well.
Interesting. How are these recordings made? What I mean is, how many mics and how are they placed. I am not asking for crazy detail here. Just a general idea. I'm wondering how you would derive 5 channels if you were not using 5 mics (or more). If we apply the same thinking as a "good" stereo recording, where the mics are approximately where the ears of a listener would be, then we would need 5 mics in an array about as big as a human head, aimed at the angles that are recommended for 5.1 playback. As a guess.
All of this ignores the fairly complex nature of the Head Related Transfer Function (HRTF) and the effect of the shape of the human ear on the incoming sound with respect to polar coordinates. I.E., something coming from behind you sounds different than something coming from directly to the side because of the shape of the outer ear.
To address what you said about my "objections": Because I have not had any positive experiences with surround sound music, I don't see the utility in providing more and more channels. To me that's attacking the problem in the wrong direction by making it more complex with more signals, more speakers, and more things to get wrong. But again, I have not heard any good examples. According to you and the gentleman who posted pictures of his setup, you can definitely achieve a good sonic illusion with 5.1 or 7.1 audio systems and recordings. I would very much enjoy hearing one some day.
Still, a good stereo system with 2 channels can produce a pretty convincing audio illusion. I wonder if 5.1 can be better, or if it's just like more sonic seasoning. Different, but not necessarily better? This is a question and not a statement.
Thanks for the discussion.
Brian.