I loved Boston but haven't been to New York. You may be better flying to Boston as the airport is just a short and cheap ride on the tube to downtown. Then get the train to New York. That way you avoid the very expensive taxi ride from JFK to downtown NY. Lots to do and see in Boston and it's all walkable. If you have time think about Cape Cod; Newport ,Rhode Island; Mystic, Connecticut; North Conway, New Hampshire; Boothbay Harbour, Maine; Salem. All great places with lots to see. We went late September and saw a young black bear on a side road in Vermont. I would be happy to share our itinerary with you if you'e interested.