Gailgs - the 24 can polar bear cooler is soft sided and the size of a carry on. However, we plan on checking it (my husband has diamond status w/delta which gets him 3 free checked bags - up to 70 lbs each). We won't come close to the 70 lb limit with the cooler.
Any big downsides to checking it? Our flight itinerary is: Pellston to Detroit, Detroit to Atlanta, overnight in Atlanta then direct to St Thomas next morning. (Can't get there in one day from here)