Is it easier to get your bangs swept to the side with longer hair, and let it stay on the side without it fall?

not really, especially if you get your bangs cut the first time, then you have to keep blow drying it with a round brush so that eventually it will stay. and if you mean "longer hair" as in the bangs [?] then i don't think Gatsby would work as well since i've seen it really only used for holding short spikes in place.