I have a large mix breed dog who's very big but has short legs (100lbs, pittbull rescue mix) - I bought the medium size and am so glad it's perfect and that I didn't need the large (which would have taken up too much room in the house I think). He curls up in it and fits so well. The quality seems great, almost like memory foam, and he can move it around and nest. I ordered the grey and it has a slight purple-y/grey tinge which I didn't like at first with my decor, but it's fine and looks great now that I've gotten used to it. it has been perfect!