This method uses magnetic resonant coupling (vs inductive which is how wireless charging works on your phone). The difference is the transmitter and receiver are both tuned LC circuits that operate at their resonant frequency, which is why this works over the impressive range shown in the video. It would have efficiencies around 80% mark based on what I could find. But yeah for RFI, this would definitely be worse than something like normal Qi charging, which operates in the 100s of KHz, while this operates in the MHz. But I think the manufacturers page says this is FCC certified? So might be not too bad.
My speakers at home hum due to my Logitech Powerplay Matt, even with a ground loop isolator. It sucks. I was kinda surprised that it wasn't an issue with this setup.