Bomarc, I'll give you my two cents (pun intended) but regardless of the theory, the spikes on top of discs have worked for me. The sound is much more three dimensional and the midrange is tighter.
Here's my theory. First, the weight of the speaker is concentrated on four very small points so the speaker is more stable. Second, the indentations on the discs further help stabalize the speaker. Third, your spouse doesn't kill you for leaving holes in the floor and everything sounds better live ;-)