It's pretty simple to get to Westchester or CT on Metro North. The Stamford Marriott is walking distance to the train station; I'm not sure if the Renaissance in White Plains or the Marriott has a shuttle from the stations; most likely they do. There is also a RI in White Plains that I believe has a shuttle, but is also walking distance to the White Plains station.

If you're flexible on your lounge access requirement, the CY in Stamford is also walking distance to Metro North, and the Tarrytown SHS has a shuttle.

The Renaissance is a nice property, but it isn't near anything, unless you have a car rental or Uber/Lyft. The Stamford properties are really the only ones where you could take in some sights/activities without transportation.