Just added one (16A version ) to my system. Had a nagging hum from my power conditioner transformer (even on a dedicated 20A line). It hummed louder when I switched my amp to Class A (higher load).Tried my spare PS audio humbuster which reduced the hum but was still present (could hear it a few feet away). Looks like my AC like had more DC voltage than humbuster could handle. Only downsides, 2 power cords for one connection and the unit itself is pricey. I got the 16A version just to be on the safe side as my system's current draw as of now is close to 7A.
