So the way I see it: if I listen to a particular headphone and the song has drums in it - do I hear the impact from the very beginning, does it sound slow and sluggish, almost farty?

Do you hear echoes or reverb from instruments while other stuff is already going on, or is the whole image too mushy to listen for that?

The phenomenon that you described, hearing something new on a high-end headphone and then hearing the same thing on a cheaper one is your ears being trained basically. You know now what to listen for, but you needed the better headphone at least once to properly be made aware of it.

If you have the chance: try to compare the focal utopia to the Audeze LCD-X. You would assume that the Utopia, given it’s price, is better in every way - but I don’t think that is the case, I would describe the LCD-X as more detailed and faster, but the Utopia as smoother and more pleasant for longer listening sessions. I do think the terms make sense, but only in comparisons with relatively large differences.