Flrnlamb:
I have reviewed the Dakiom feedback stabilizers. They worked quite well for me with the original B&K ST 140 amp, and also helped with the Odyssey Stratos Extreme Monoblocks. At FIRST, when used with the Odyssey Extreme Monos, they seemed to truncate upper end detail ever so slightly, but still improved the overall sound, including the bass, so I kept them on. LATER, after several weeks or so, when I retested them again (with and without), they did NOT seem to truncate upper end detail, and just made the music sound sweeter, and overall better. Not sure why that happened but it was undeniable to me and my instrument-playing wife. The folks at Dakiom seem to think that "burn-in" is a psychoacoustic phenomenon but that runs contrary to my experience with their product. Also, the boxes still helped the Odyssey Monoblocks, even though those amps use "very little" negative feedback, according to Klaus Bunge, when I spoke to him on the phone.
Some of the more recent statements made by Dakiom on the Audiogon site seem a little "odd" to me, but they do make a fine product worthy of audition.
Be sure to read the comments made by Tvad in response to my original review also, as he had some intelligent things to say. Ultimately, this is a subjective topic, to say the least.