FWIW, here's some feedback I received from a customer after using this product:
They said that it takes forever to warm up. It was installed over a concrete floor and in the Seattle area where it gets cold but not Minnesota cold.
In the photo below, you can see that the wire is a Suntouch wire ran at 2 pegs and the wire is ran over every bit of the floor.
I'm not saying this product doesn't work but I am saying that it may not solve the problem that one is hoping to solve. Probably, using a foam board underlayment as an insulator would yield better results.