They are pretty lousy. They're like chocolate-flavored wax. I don't remember them being so bad when I was a kid.

Oddly, there's nothing in the list of ingredients that stands out as being that odd. It's Sugar, Milk, Cocoa Butter, Chocolate, Soya Lecithin, and Vanillin. The first four are obvious. Soy lecithin is an emulsifier, which probably just helps keep them from turning white, and vanillin means "artificial vanilla extract".

The only thing I can think of is that chocolate is a mix of cocoa solids and cocoa butter, so it effectively lists cocoa butter twice. I wonder if they've distilled the lower-melting-point fats out of the ingredient they list as "Cocoa Butter" in order to make it less melty.

The plain milk chocolate bars are still pretty good. It's clearly different chocolate.