I have two Yetis; hands down, they're the best I've ever used. Heavy little bastards, but worth the price. The 65qt is probably the best size for the cost. We kept a block of ice for almost two weeks, and I'm wondering if I brined the meltwater if it would remain cold even longer!?
Here's an ice tip that might prove helpful. Stuff stays much cooler in my Coleman cooler if I freeze gallon jugs of water before taking off for a trip. With the ice contained in the jugs I don't get a cooler full of waterlogged food and I have fresh cold drinking water as the ice slowly melts. I think having the solid ice contained actually keeps it frozen long, too. The jugs still have ice in them 4 - 5 days later. If the Yeti's a better cooler, I'm sure you'd have ice days longer!
Coleman Max still had ice after five days. Packed it the night before the GR trip. Blocks still kicking after four days of over 90s heat (travel/float/float/float/travel). I still want a yeti or Yukon.
I think a key is prep. I, too, use half gallon juice jugs for ice and I put two in the day before and replace them when I pack to go. I have been very happy with Rubbermaid coolers favored them over Igloo and Coleman, but i'm getting the wants for a Yeti or Engel.