Stayed there for about a week at the end of August. Great location for my business mtgs which was located in 1 Main Street at the mouth of the Longfellow Bridge.
Took full advantage of the close proximity to the Charles by walking the circuit of sorts along both the Boston and Cambridge sides and crossing using the Longfellow and one of two westward bridges. The second bridge was beyond the Hyatt Cambridge. Beautiful setting.
My room was on about the 16th floor, I think, and had a great view facing Boston. It was best as night fell on the city. Fairly nice property with the new, comfortable Marriott Bed in the guestrooms.
Used the T a couple times to get to Harvard Square. Cool Independent Film theater in Kendall Square. About a five minute walk west on Main.
Enjoy!
AtlMan