I have a bunch of smaller cooler types and IIRC they claim to keep things about 40 degrees cooler than ambient. I have one that makes ice, sort of. it came with a tiny aluminum ice cube tray which you set on the bottom, then put an insulated divider over it and wait. but it actually does freeze. no practical use however.
mine are more like that Koolatron fun that was at that link.
I do NOT consider any of mine to be a waste of money. truck stops sell a bunch of them, so they must be liked by somebody. like my refrigerator in my RV, I always put cool/cold things into it.
bumpy