Any of these roto mold companies making 10 day ice claims are dealing in black magic, I use some of the more popular name brands in my catering business and they all perform about the same.
RTIC is my go to source whenever I need replacements just because of the deals they offer from time to time, but unless all your adding is one can of soda and filling the entire cooler to capacity with ice none of them are going to hold cold for more than a few days with a decent load of consumables inside leaving less space for ice.