McDonald's Frappe is what you should expect
I got the caramel Frappe, which came piled high with whip cream and caramel drizzle. I loved the first sip. But as I drank and the drink melted and the whip cream blended with the coffee-caramel mix, it started to taste just like McDonald's vanilla ice cream with caramel blended in. McDonald's ice cream is fine, but it wasn't what I was in the mood for.
Some might argue that Starbucks' Frappuccinos are just like milkshakes, but they taste more like blended coffee to me. The Coffee Toffee Twisted Frosty is definitely ice cream, and Panera's Frozen Caramels are borderline.
I'll probably have a Frappe again, but it will be when I'm in the mood for a coffee-caramel milkshake.