It really just depends on which formula style you prefer. They are both sheer lipglosses, but the Sweet Gloss comes in a lipstick-tube formula and applies more like a sheer lipstick. The Big Smile Gloss is a little shinier than the other and it is in a click-stick applicator tube. Both provide about the same amount of pigmented color, but the Big Smile is more shiny than Sweet Gloss.
I hope this answers your question.