If a source reproduces something that is almost/resembling a square wave then that points out something. The more exact the better, but in real world it is difficult to do this (or perhaps measure it that exact). Tyll has a very good explanation on this subject on Innerfidelity. Two dimensional data would not give any more information on how well a source could reproduce a square wave or whatever wave for that matter as I see it (doesn't need to be square, but it is supposed to be easier to see a difference in a square wave). Still I cannot see how a decay plot can describe how tight bass is or other characteristics. So imo it makes more sense than looking at a decay plot.
Edited by Deni5 - 3/7/13 at 8:30pm