It took a year before we were sold.
But even at the very beginning we took notice. There was never, ever, a wet spot under our mat. Ever. Wow. We are BIG sweaters. Big. Ask anyone. We pour. At one point in our Bikram Yoga practice, we were offered a 3rd towel. We sweat that much. So having a mat completely impervious to liquid is a wonderful thing.
But it is what we noticed after a year that has made us believers.