That really is a subjective one that I'm sure will vary from person to person and flavor to flavor. I myself use most liquids in 24mg but use most of the sweeter flavors in 30mg. I get all of my Ms Ts stuff in 30mg to get the TH that satisfies me personally. However I know some of them like Loganberry, Orange
juice, and a few others would give me enough of a TH in 24mg but I like the killer TH I get from them in 30mg.