Originally Posted by platbrownguy

Both the Westin and the Marriott are perfectly adequate properties. If you're worried about things like parking costs, I would just pick whichever one is cheaper. As an AMB I didn't a true suite at either hotel so I doubt you'd get more than a junior suite type of upgrade as a Plat. You'll get lounge access and, as noted above, the Marriott's breakfast offerings were fine and actually included real scrambled eggs instead of liquid egg product.

Unless the rental car isn't costing you anything (like if it's a week-long rate that costs the same as a 4-day rental), you should just drop the car at BOS once you get in from NYC and not worry about parking. For the day you might go up the Cape, just grab a car from Avis (there's one near Copley) or Enterprise (there are various locations) for the day.

Note that the Back Bay bus goes from Logan to directly in front of Copley Place -- it's free from Logan, and it's $3 to Logan. And it drops off at the terminals unlike the subway or Uber/Lyft.