Update
This past Sunday I listened to my system for an extended period and at higher (normal for me) volume levels compared to previous sessions with the Stillpoints Ultra installed. My appreciation for the devices' effectiveness, particularly the Ultra SS under the speakers, is substantially increased. My sense is that the suspended floor underneath the speakers and perhaps even the walls and ceiling vibrate less, contributing to a significantly more articulate overall sound. Bass frequencies are still presented powerfully, but they seem to pressurize the room differently (more ideally) than before installing the Stillpoints Ultra. I am unable to identify a single drawback from using the Stillpoints, except of course a lighter wallet. Call me highly impressed.