While I truly appreciate and agree with how well the Sheraton Boston treats Platinums, I had an experience there on a stay this year that made me take pause (which I detailed in another thread).

In short, you may want to avoid the floors adjacent to the pool. The moisture, according to the hotel staff who came to deal with the creature I found in my closet, clinging to my dress shirt (apparently having gotten a ride on a housekeeping cart), is attractive to cockroaches. Nothing serious, but a bit disconcerting if you happen across one.

Other than that, I've found the Sheraton Boston a convenient and less expensive alternative to the Westin Copley Place on my trips to Boston.