I've found that music recorded in stereo sounds great played back in stereo. Additionally, mono recordings are really best played in mono. That is the truth I live with every day.
The truth is not only difficult to define but relative and subjective in this hobby. Good luck finding your truth.
My point was that the same recording played in mono or stero has a different presentation of the soundstage due to the miking techniques. Some stero recordings are miked in a way that it seems artificial or HiFi sounding. Take an old RCA Living Voice recorcing for example. The sound emanates from the middle with a continuity in sound as opposed to the sometime ping pong effect of the stero version. IMO the older Mono recordings reveal a truer sense of the Orchestra or small Jazz group than the same mix in stero. However this is not always true. A well miked stero rendition will offer a 3D type effect creating a sense of time and space.
Today multiple track recordings with instruments and voice recorded separtley and mixed back to fporm the whole is sometimes not very well done. Then again when the recording engineer gets it right its pretty close to the real deal. Go figure. I guesss it depends on the process and who is doing it.
If you can listen to a mono recording through a mono cart. and the preamp set to mono of say that RCA we might all be very suprised as to the realism it presents. Mono done right can be a wonderfull experience sometimes more so than the stero rendition.
rollo