Thanks again all ya'll, as for color Yellow Goldwings are the fastest, wrong forum
I really like the Cobalt Blue Pebbles, as for the grout vs tiles could go either way concerning the coefficient of thermal transfer depending on the grade of the grout, amount of Al vs s SI, etc. But it is an interesting conversation concerning the delta of the heat transfer between the too, especially with the more exposed grout. Would be an interesting test. Maybe Dennis will pony up 2 units and i can arrange the necessary equipment to monitor it over the course of time. Might be wishful thinking though.
Haven't pulled trigger yet but pretty sue will be the big bad 3