Mine arrived from China today. They look and feel really good. I was concerned that they might have too much of a tactile, rubbery feel, but they don't at all. They fit quite tightly over the key fob - a bit of a struggle getting them on, but perfect fit and alignment with the fob, and the buttons I tried perform properly. They should provide some level of protection against damage by drops.
It will be a challenge getting the key out if I ever need one, and I'm wondering if I can get a couple of regular keys cut to avoid that potential need.