Bought a 28 and a 55 for off shore fishing trips in Massachusetts.  I regularly load the 55 on a Thursday and Monday it is still holding 80% of the ice.  The 55 holds fish, it is opened only a few times during that period.  The 28 gets loaded, half ice/half food on Thursday.  We use it all weekend for getting lunch and drinks out.  Regularly clean it out on Sunday night and half of the ice is still there, good ICE cold drinks in the bottom for Sunday night football.  Thanks!!!!!!