These two seem like similar products in that they lightly polish and protect the surface. How would you rate them against each other? Are either good just by themselves or best used with something else (i know the klasse is often used with the HGSG). Also which pad would be best to apply this type of product and how much should be used? What toppers would be good to use with either or? I have seen p21s often bundled with the klasse. Follow with carnuba or sealant?