Excellent quality and construction.  I purchased the medium sized bed for my (full grown) cat, and it turned out to be the perfect size.  As soon as I put the bed on the floor, my cat immediately stepped in and started doing her little front paw dance fluffing up her sleeping spot.  The sides are firm, but they are somewhat flexible allowing my cat to stretch-out and push against them.  She seems to really like to soft interior lining and curls up burying her nose into  the sides of the bed.  In my cats case, it has become more than just a bed, it has become her hangout space, almost like her own personnel spot, - hard to describe, but other cat owners would understand.