I have A huge igloo that does okay but only in the shade, direct sunlight melts the ice in a day or two. My hunting buddies have yetis and you can leave them out in direct sun and still have ice for 3-4 days in the summer. Hunting season and ice will last for weeks in the shade as long as you don't open and close it all the time.
my neighbor bought the hopper 30, while very expensive I have seen it keep ice in the middle of summer in the back seat of his truck parked outside for 5 days and the water was still very cold 7 days later, beer was still very chilly.
on our recent trip to Nebraska we did a test with the colster from yeti. After 1 hour a beer without was on the verge of Luke warm, not very good. With the colster it was like it had just been pulled out of the fridge. Completely worth the money.