great answers here already, wanted to add a couple of points: You might see a little bit of traffic on Winter street closer to rt 30 because of the Westgate Church. It's nothing overly busy that will create a traffic jam. That will be your (small) weekend traffic add on. And river's school area will be quiet during the weekend.
Winter street is tree lined, so noise gets softened, plus if the house has new windows you will not hear the pike inside. When outside, noise is more a matter of personal perception and general knowledge that the highway is close by. It also depends where exactly the property is located. I have seen a house in Wayland / Natick area, that was built literally in between the pike and rt 30, you could hear and see both roads.
I personally like that Winter street is close to both Pike and rt 30, it gives you more options when choosing your itinerary. it's still a very quiet and beautiful street.