I think that I would need to see all of the engineering data to be able to determine if 5 is better than 3 pieces.
What is the most important thing is -How does it perform for YOU- that is all that should matter. Most people could not tell you how many pieces or layers the ball they play has. I know guys that don't even look at the ball, they just play whatever they pull out of the bag.
Don't get twisted up by the marketing speel, play with the ball that works best for you, be it a ProV1 ofr a Pinnacle or anything else out there.