I recently tried a Silent Angel Bonn 8 network switch with LPS (£600).
It has made a much more significant SQ improvement than i was expecting. Similar to the level obtained from an upgrade in a high quality power conditioner or regenerator.
After several hours of listening i switched on the projector (fed by a sky box linked to the Bonn N8) and the images were much sharper and blacks so much darker; it's a cliche i know, but i really did have to reset the the picture controls.
There is a review of this switch on "audio science review" where the test results conclude that there can be no improvement. This is followed by several pages of presumably well qualified people laughing at audiophiles who fall for these scams.
Their certainty is impressive.
it's an interesting irony that we all share a interest in the technical side of this hobby with the aim of getting better SQ and yet many highly qualified people will have poorer sounding systems because they simply will not try a product (at no financial risk).
a scientifically minded person should surely see the very large data set of people who independently report positive reviews and wonder, how likely is it that they are all lies and expectation bias?
Perhaps it is a fear that it might contradict what they (don't!) know?