Both the frozen and the cold get the topping from the same dispenser, so they're exactly the same. They are really delicious, next time I get one I'll ask for extra topping if they allow it.
They will however NOT, not put topping on. It's against their rules to make a butterbeer without the topping. One of my daughters hates cream and anything that looks/tastes like cream. She asked for one without it and they said no, you have to take the topping out yourself.