Acrylic and Gel actually have the same chemical makeup. Acrylic is a liquid and powder that form a hard  protective layer when combined. You can kind of think of  gel  as a pre-mixed acrylic. Gel has to be cured under an UV light, and its a little more flexible than an acrylic nail. Gel Polish is a hybird of  gel and nail polish,and it also has to be cured under the light. Which type is best depends on the individual client. Also, any type of  nail enhancements can be long- lasting with proper application.