I love this blanket! I used on the beach, and it's very easy to brush off the sand after you are done using it. Of course, it gets wet on the fleece side, but it gets dry very quickly. The fleece side is very warm. It's big enough for two average people.
I LOVE that it's foldable and easily converts into a little "bag" you can carry with one hand. So far I've only used it in my backyard when I want to sit on the ground without getting grass stains :) but I could definitely see myself taking this to the beach, camping, traveling, etc. While it is indeed waterproof, I notice that leaves and other dry plant material sticks to the fabric side quite easily. Otherwise it's a great outdoor blanket.