Slow churning ice cream allows the ice cream to maintain flavor and makes for a creamier ice cream. When they make ice cream they keep it frozen even in the making process. This allows for more ice crystals to build up and make for a crunchier ice cream. When you slow churn it requires less freezing so creates a smoothr texture.
The method that they use to make it is what makes it lower in fat and calories but even so, the method makes it taste so much like regular full fat Icecream. We actually enjoy the slow churned more.....the caramel one (dulce de leche) is wonderful.