@thomasfuchs Ehh... it can be both.
My Ikea burner is definitely worse with some pots, but it makes the same screechy sound even with the single-layer (non-laminated) kettles I have. Heh, and for the hell of it I tested to see if it would work with a baking sheet I have. Yes, it does and yes it made the same noise as always.
I have little doubt that it's worse than a proper stove, but still. Radiant just gives a little bit of a hum.