Both are relative new communities. Stonewater is little easier to access several major highways, I-540, I-40, I-54, and I-751. It is only about 10 minutes to South Point mall. It is in city of Cary; Providence Place is little tucked away and is little closer to railroad along Church street. It is in city of Morrisville.
I'd suggest to work with a buyer agent who have done business in both places. Not only they can have some insight knowledge about the community, the past sales information, and the latest market condition in general, but also can negotiate on your behalf. The commission is directly from the builder, not from buyer's purchase price. It is a free service to you. Remember builder is representing the selling side.
If you would like to find out my experience of working with my buyers in both communities, I'd love to talk to you.