Maestro faceplate - does it make a difference?

Some more data to consider:
I built a power box with 6 outlets and put a fancy stainless steel faceplate on it so it would look nice. I then decided to try a lightweight nylon faceplate after getting rid of ferrous materials in my power cords.. the nylon faceplate definitely sounds better. 

As for which faceplate you should get.. that's beyond my paygrade

Just to mix things up a little the ones I sell are actually resonantors. I know what you're thinking - why would you want to put something that resonates there?  Thus, you can employ them on UNUSED outlets as well as outlets for audio devices AND outlets for non-audio devices with good results.

Or maybe Geoff buys his ceramic wall plates on Amazon https://images-na.ssl-images-amazon.com/images/I/41vDumcXTWL._SX425_.jpg for $3.82 and offers them up to audiophiles that visit here or his website for $30.00. If I were to use these plates I would upgrade and  use a non ferrous brass machine screw for $.59.. Tom

Tom, are you high? My audiophile outlet covers are treated a number of ways. Sorry but I can't actually tell you how. Then I'd have to kill you. Do you really think I have a kiln here and produce my own ceramic duplex covers? That's special.

Most treatments are $5.00 per pound less shipping to and from. How many of these = 1 lb. ? Tom