Suntouch is what I use. Suntouch is a quality matted-wire product that installs easily. I then embed the system in Self Levelling Compound which also serves as the tile underlayment. All systems of this type require a "thermal-mass" for best effectiveness. The SLC becomes the thermal-mass.
They have a system that operates on standard 120v house current with a programmable thermostat for pennies a day. Once installed, the floor is raised 3/8" ahead of the tile. I have never had a customer complain about the minute elevation change required to install the product and they all seem to love the product. Never one complaint in about ten years of using this type system.
I know this sounds like an ad for the product but it really isn't. I have nothing to do with the Suntouch company other than being a customer of theirs and a professional tile installer.