We got the XL for our 95 lb Labrador Retriever and he loves it.  Plenty of room for him to stretch out.  Excellent support and head rest for a large headed dog.  He loves it and we love the way it looks - got the sueded rust color and it's actually very elegant.  This is a well made, durable bed.  You shouldn't have to replace it for a long, long time.  Highly recommend.