Really Does Work
I'm writing this review as a "reverse warning," because the Primacoustic monitor pads may seem like they could be an "audio snake oil" product, embraced by those who think running a green Sharpie around the outside rim of a CD makes it sound better. But these pads are the real deal and make an audible and very desirable difference, particularly with imaging and bass accuracy. The improvement is apparent with any speakers I've tried. I used them previously on ADAM speakers and am now using them with KRK's VXT 6 speakers; the improvement was about the same for both. While not exactly cheap, these pads are a simple, effective way to upgrade the accuracy of what you're hearing.
True story: At an AES convention, Primacoustic had two pairs of speakers set up, one pair without and one with the pads. The guy doing the demo would switch between them. I heard one of the attendees arguing with him because the difference was so obvious he thought there HAD to be some kind of trickery involved. I went up to the attendee and said "Look, I have nothing to do with this company, but I own a pair and the difference really is that obvious...there's no trickery." As a studio accessory, these pads are second only to an uninterruptible power supply for my computer :)