Local guy that sells Yetis told me the Yeti really won't keep ice...
a whole lot longer than an Igloo Marine or other good cooler but it will last pretty much forever. The problem with coolers is not the insulating ability, it's the opening of them. I have an Igloo Marine cooler in my boat. If I don't open it much, it will keep ice for about three days in the Summer. Unfortunately, when I'm on the boat, I open it a lot to get beer out so ice lasts about a day and a half. Yetis are about the same but if you don't open them, they will keep ice for 4 or 5 days.
I like the Yetis and the other high end coolers, but I can't make myself spend the money to buy one that will fit the spot in the boat where my Igloo is. I also don't want to have to worry about my cooler being stolen while the boat is tied at the dock overnight. Cooler theft is becoming an issue on lakes and around the coast.