To shortspark:
After much experimenting with room placement and installing/uninstalling the spikes, I have found that my HT3's sound best in my room without the spikes. They sit on my wall-to-wall carpet, which covers the concrete foundation of my house. I think part of the reason for the better sound without the spikes is that the midrange and tweeter drivers are better aligned vertically with my ears when I am sitting at my listening position. Bear in mind that the improvement in sound without the spikes is quite subtle, but audible nonetheless. Granted, I am foregoing the cool look of the spikes. But, it's worth the trade off to get the improved sound.
Regards,
Bob