The white part of the Oreo has no flavor whatsoever, but adds a nice bit of softness to the hard chocolate part. The texture of the entire cookie together is fantastic and I can't have one without the other. The chocolate part is tastier because of the chocolate. The white part is soft and tender to balance out the crunch.
Without the cream in the Oreo, I would never buy them. I often "share" my double stuffed with my cat, giving her one of the brown sides from each cookie thus turning my 2 double stuffed into a quadruple stuffed Oreo. I even found a recipe for a cake/brownie icing that tastes just like the Oreo cream filling. I make a double recipe whenever I'm using it on baked goods just to have a bowl of Oreo cream to eat by the spoonful!