Well, here's what I ended up doing:
The spikes I got were these:
http://www.parts-express.com/pe/show...number=240-725
The price was right and they seemed to work pretty well. They pierce right through the carpet and padding to the concrete below. I used some scrap 1x3's screwed to my round base to make 3 spike feet that stuck out a couple of inches, such that the round base was roughly inscribed inside the triangle.
Three points was the way to go...there's definitely less sway now. Oh yea, I also cut the stand height down so that now the overall height is about 1 inch lower than before.
Does it sound different? Well, I'm not sure. I'm noticing maybe a bit more detail in the upper mid range. Maybe the base is slightly clearer, or maybe I'm being optimistic! I need to do some more listening and checking. I'm probably due to dust off Room EQ Wiz as well since it's been awhile.
Appreciate the responses on this.
Thanks
Chet