How are these bags? I've heard they have either poor quality zippers or too little insulation? I THINK, but I may be wrong. Otherwise....sweet deal and probably doesn't matter as I have used a tarp before with satisfactory results.
I had one and hated it. Fish Bags are made to keep the fish cold and submerged in ice. For some reason unlike every other major bag they have vent hole in the corners which allows any melted ice to drain out of the bag.
Bad design IMHO this not only makes the bag leak during transport but also allows more warm air into bag to make the ice melt faster.
This would be my only choice, the best bag on the market and its used by most tournament teams. Maybe a little pricey but better than buy multiple bags to find one you like. The Canyon Bag is absolutely waterproof and gaurentees to keep 90% of your ice for over 24 hours
I use the Reliable Fishing Bags and have no major complaints. I have noted that their smaller bags are not completely waterproof which can be an issue with fish like tuna and the amount of blood that comes out!