Lots of cacao solids doesn't make a bar of chocolate better or tastier. It's a question of individual taste.
The nutritional composition of milk and dark chocolate, ie the quantities of fat and carbohydrate they contain, make a difference.
> The higher the percentage of cacao solids, the more fat a bar of chocolate contains.
> The lower the percentage of cacao solids, the more sugar it contains.
A bar containing 60% cacao solids contains slightly fewer calories than one containing 80%, so don't believe everything you hear!