Both my Fur-Kid and I LOVE this bed. As soon as I put it up, she jumped on it and fell asleep. When she gets too hot, she kicks her bedpillow off the cot and sleeps on the mess which provides air flow. She is 40lbs and I got the large which perfect for her size. She has plenty of room to stretch! She uses the sides for pillows. It was easy to assemble. Hands down, best purchase!