Scout started sleeping on it right away. In the past with other dog beds, she'd sneak into my bed in the middle of the night when I was sleeping. Now she stays put in her bed through the night. (I think she appreciates not getting kicked in the middle of the night by her human)
The bed is easy to take apart and wash.  The only thing that would make this better is if it was water proof.  Scout has spay incontinence and it's challenging to wash the memory foam.  I'm planning on buying a pillow case encasement to put the foam in then put it inside the dog bed. 
Otherwise, the material is very durable and the medium is large enough for her to stretch out in.
By the way Scout is a 1 year old, 37 lb Red Heeler Mutt Mystery.  She's pretty lanky and likes to stretch out to the max, but the Medium suits her well.