A Synergistic Reference has beaten everything for me, for either of my amps (KAV-250a, or Rogue 88). The Essence was only marginally better than the Pro Flo, so if you like the sound of the Essence, I'd save my money and get the Pro Flo. I haven't tried the King Cobra yet, but at this rate, it might be a while. I did like the SR much better than the Black Mamba and Sidewinder, and quite a few other cords. It's unbelievably better than the standard Master Coupler, to my mind. The standard one was slow and distorted, and the ref is just as dynamic, and seems to do everything else right too. I have no idea what amp you have, or what your system is like, etc.
