Ive owned one for over a year, and Ive used it about a dozen times.  Its really great for keeping drinks and sandwiches cold when were hiking or off-roading close to home, and don't want to mess with the cooler and ice.  I add a couple of frozen water bottles to help it cool down and stay cool when the power is off.  Its lightweight and a convenient size to quickly load and unload.  A couple of times Ive used it for long drives over several days, just to have access to cold drinks without having to pull over to get to the cooler.  It worked great for that, too.