It's between the Westin and Miyako. Tokyo Bay is essentially Tokyo Disneyland and Yokohama means a (fairly) long train ride in/out Tokyo every day.

Westin is by far the more luxurious hotel and right beside (kind of) the metro station. Miyako is a "salariman" hotel (which means function over form) and isn't that close to the train station.

If you've got a boatload of points, do the Westin. If you don't mind taking the Miyako shuttle and/or a short taxi ride to the metro station, the C&P for Miyako is the better financial deal.