I have some.
I have the EarthCalm home and the pendant. I also have the Quantum Home.
My bed is also "grounded."
For myself, I can "hear" quite a few frequencies that are way outside the norm. When they put up some new giganto cell/wireless/sat/? towers in my area I could "hear" them at first.
I cannot tell you how many we have in our little area in the suburbs. It is literally ridiculous. Dozens, and at least 4 mega tours with tons of crap on them.
I didn't tell my DH I was doing it and he really doesn't know what they are for.
However, his sleep has gotten better. He is from small town-small population province. When he grew up he had almost no exposure to anything of this type. While some of the other things we were doing to improve his sleep certainly helped (CPAP), I notice that when we left our city his sleep was better. Much better. Even when he was uncomfortable. Even when he was in pain from his back. I started to wonder if the schumann resonance and some electrical quieting might help him. And it does.
I'm sure that this thouroughly puts me into the tin foil hat category. Whatever. Schumann resonance gets used on MIR even. The silver mesh I have on the big windows on my house to block solar gain I'm sure help that reputation along too.