I’ve had an 80lt for a few years and use it for both fishing, camping and parties. It a great esky and I would highly recommend for the price. The techni ice worked okay but shouldn’t (can’t) be used with fish, they absorb the fish smell.
I use 2lt coke bottles as ice bricks, half fill the esky with drinks (pre chilled of course) and ice bricks, place a wet towel over them, load up the rest with 2lt ice brick and drinks and it last for 5+ days. The towel was something I seen years back and stops warm air getting into the bottom half of the esky when it is opened. The larger the block of ice the better, and it doubles for drinking water. Probably last longer with 3lt milk bottles.