Firstly, Galaxy and Cadbury chocolate taste different, so a Ripple and a Twirl which are the same type of product are of different tastes, similar to a Cadbury Dairy Milk bar and a Galaxy bar.

But a flake is different, and not just a naked twirl. Different and increased crumbly texture as well as different type of chocolate, you supposedly can not melt a flake, unlike a twirl which you can.

And Flake always had the better adverts when I was a kid.