For my test of different variables I chose to see if I could hear any difference between the three tests I had chosen as a good representation of stereo when I put them in mono. To my ears, all of the original tests sounded basically the same, with only very minimal variations on each other. While I could hear the stereo effects in the localization of the dings, not much else seemed to really make it "stereo" sounding. And the dings were sort of tempermental, you could tell the direction of some, but not completely all of them.
So, to test my ears, I compared the same tests in both stereo and mono and noticed an immediate difference between the two. In creating a sense of space, the stereo versions win hands down, the mono versions sounding flat in comparison. Of course, hearing the sound surrounding your ears (in stereo) rather than being duplicated into both ears the same (in mono) creates the feeling of actually standing in the room because it mirrors how a person would actually hear, each ear picking up on different sounds based on their positioning and putting them together to create a composite of the space.
As for the localization of the dings in mono vs. stereo, I didn't hear as much of a difference as I would have expected. For whatever reason, I could consistently hear more difference in the location of the dings between 1-4 in the stereo recording. I'm not quite sure if this is my own mind just subconsciously interperating the difference between hearing the dings from the left to the right side as thinking that the right side dings are more localized. Or if there is a specific technical reason for this. So in the mono versions of the tests, I didn't notice that much of a difference in hearing the dings on the left side.
I thought that maybe listening to the recordings in mono but still viewing the animations which illustrate where the ding is coming from in the clock positioning would fool my mind into thinking that I heard it the same as in stereo. And while it did a little bit, there was still an obvious difference when watching the animation and listening to the stereo version.
All in all, I now appreciate much more fully the value of stereo sound recordings and their ability to recreate and place the listener in the space of the original recording.
I recommend listening to the mono versions first and then to their stereo counterparts immediately after to get the full effect that the stereo brings.