This type of coated nylon is usually chosen for racing spinnakers, because it is strong for its weight, doesn't let any air through (so no loss of power), and doesn't absorb as much water (weight). These are all things related to optimum performance (speed). These same attributes would also apply to Contender's racing spinnaker material ("superlite" and "superkote").

There is a price difference. You can expect to pay considerably more for this kind of premium nylon.