We always opt out of prepaid gratuities and tip whom ever we feel did a great job at the end of the cruise. If the room steward was just "ok" then ther tip is small and if they are great! well you get the picture. Also we NEVER tip the maitred, since you never see him until the end of the cruise with his hand out. Also they are not a low level employee, I'm sure his paycheck is more than enough!!!!!!!!!!!