Which hotel is nicer and in a better location?

I would opt for the Marriott Copley. The BHH is probably nicer and sits right on the edge of the harbor, but the Big Dig is literally outside the front door.

The Marriott Copley is in a nice area (Bay Bay) that is filled with shops and restaurants and nothing in Boston is too far away from anything else, so you will still have easy access to all the historical sites.

what are you interested in doing/seeing? kids? how many in party? ages? both are great, but have a different flavor- what are your intersts?

Marriott Copley. I've stayed there often on an annual basis. You'll love it.

The Marriott is like every other Marriott on the face of the earth. But the Boston Harbor Hotel is a beautiful unique place. It is the centerpiece of the Boston Harbor. The view is awesome. The service is great. Its also close to Fanieul Hall/Quincy Market and the North End. You can walk to the Common, Chinatown, Filenes Basement. Screw the Big Dig.

Thanks to everyone for the information.
I appreciate it.

To respond to Jillie questions.
We are in our late twenties, we like bars not clubs. No children.
We were thinking of checking out the Samuel Adams Brewery. Any suggestions would be most helpful

marriott copley

Probably go Marriott Copley. BHH is beautiful but Copley little more comfortable and convemient to lots of stuff, especailly Back Bay/Newbury Street where there are lots of great restaurants & bars (not clubs). Good shopping and fun stuff.

Can always head over to Fanueil Hall (closer but not next to Boston Harbor Hotel) for an afternoon of fun there quite easily from Copley. Copley more in "heart" of city (if there is such a thing) with plenty to keep you going. Have Fun & Enjoy!

I'd opt for Marriott Copley, and I think you'll enjoy the Sam Adams Brewery. We had a bit of a hard time finding it. I can't imagine getting there without a car. Newberry St. is interesting. I also recommend getting over to Cambridge, the north end of the city for great Italian food in very casual settings, and if you like history, follow the red line through the city through all the historic landmarks.

We stayed at the Marriott many times, and then a month ago, tried the Westin which is next door. WESTIN had same kind of rates, in fact a bit lower, and much nicer guest rooms, better staff, better food, etc.