Originally Posted by The Dark Knight
I'm not taking sides here....and I understand your desire for the purity of the sport over technology.
However the answer to your question is : no.
All shots even flat shots have some spin on it.
I grant you that a ball coming in waist high you will hit flat with the same RPM regardless of the type of string.
However not all bounces are created equal....for example if someone hits a low skidding slice at you then you must lift that ball to get it over the net. It cannot be hit flat.
I hit those balls with either slice back or relatively flat and hard which goes over the net by an inch. In either case, poly is not going to help me with spin.