Great value and location!
We stayed at the Copley Square hotel this weekend based on the recommendation of a friend. From the moment we stepped out of the cab, the staff was very friendly and helpful. Check-in was fast and efficient and the front desk clerk even recommended some great options for late night dining outside of the hotel. We attended the wine reception and were very impressed with the fact that the General Manager was there to host the reception and personally greet the guests. We have not received that kind of personal attention at more expensive properties.
The decor was tasteful and we were very pleased with our room. Extremely quiet, tasteful furnishings, comfortable bed, and clean! Even the toiletries were special. I especially appreciated the magnifying mirror near the sink. The only drawback was the lack of a coffee machine in the room; however, the complimentary coffee in the lobby was of high quality and hot, much better than the machine brewed coffee in most hotel rooms. We ordered room service for breakfast and were very pleased with the speed of delivery and the quality of the food. 
If you are looking for a comfortable hotel at a great value in Back Bay, I would definitely recommend the Copley Plaza hotel.