Wendell, I think you misread the post, he's looking for others who took the plunge, he hasn't yet.
Underdog, I bought a number of Harmonix footers in the past (less expensive ones, though), but only after I tried them and heard them in my system. I even used four of them under my Duntech Princess speakers for a long time, principally because I was not going to wreck my floors using spikes (this also wound up breaking the footers as well after a few years). Ultimately I stopped using them in all applications--while they clearly changed the sound, it was not necessarily for the better, and different types of isolation devices worked better in the applications where I had used the Combac feet. I do not think, from my experience, that their high price is justified by their performance, but that's just my opinion.