I suppose I don't really understand this topic very well. From what I hear, I don't see why there is enough RF in the house to notice a benefit. What the the metrics on RF which is audible? Any links to research on that?
Also, I'm not sure how one of the products above, which has isolation transformers, would help, as I've heard that all ethernet connections are transformer isolated -- it's part of the design.
In other words, I don't really get why these things are needed, from a technical standpoint.