How well do FRER tests work for you?

I love FRER tests, I think they’re easy to read and accurate plus I know pink line tests are just better about less evaporation lines. Anyway, how well do they work for you? Like the box claims 6 days sooner than your missed period but isn’t that only like 70% accurate that early? Did anyone take it that early and get a positive?

Tomorrow will be six days until AF.