There are lots of great detailed reviews so I will just add my 2 cents regarding our most recent stay. This time we were upgraded to a Jr. Suite and the room was fabulous! The rooms all of a luxurious and romantic style and the addition of the sitting area was a great bonus. If staying during winter the ability to walk into American Standard without stepping outside is very nice. They have a large bar area and serve great cocktails. Breakfast/brunch there is always a nice way to end the weekend.
My favorite hotel in Boston!