Ordered a set for my wife and I (more for her) for Christmas. And I have to say they are the coolest looking mugs I've ever bought. The wife loves looking at the coffee sitting in the mug. The mugs do a great job on keeping the heat away from your hand ~ you'll only feel warmth, never hot.
As mentioned in other reviews, yes, they appear to be fragile, so I pay special attention when hand washing them. I wouldn't put them in a dishwasher either. Just my recco.