I have radient heating throughout my house, & I have both hardwood & tile; as for heat, radient heat is the BEST heat by far, the most efficient & the most economical to operate, radient actually heat the objects & they in turn radient back to keep you comfortable; you do not have to keep the thermostat as high as you would a hot air system or baseboard hot water; the floors actually do not get hot, actually lukewarm, comfortable, my newfs love it, I can lay on the tile in the winter or walk with bare feet, I would highly recommend this heat to anyone, only it is the most expensive of the heating systems, but, what price do you put on comfort? The radient systems that I have been installing in some of my projects are using hot water with gas fired boilers, the water temp is set to go no higher than 130 degrees in the heating loops; we also use the boiler to supply domestic hot water via a storage tank (AMTROL).