Okay stay, average but very loud cleaning lady
Let me start by saying that I travel all the time for my work and I also have done some backpacking. I have stayed in different type of accommodations, anywhere from hostels to a Five-Diamond hotel. I can make a difference between reality and unrealistic travelers expectations.
Not too sure what to say about this hotel. We paid a $150 a night (which for me is a lot for a 3* not even downtown) but compared to other hotels in Boston, it was deal. So I guess we got what we paid for... for Boston... 
ROOMS: They were big and clean. Bed were okay. Obviously not the Marriott comfort but I have slept in way worse beds. It was clean. Internet was on and off but it was better than having nothing. 
STAFF: I cant even begin to tell you about how the Comfort inn needs to do a major cleanup with their staff and be stricter. For starter, the cleaning staff was so inconsiderate to the customers. As I mentioned before, I travel for living and for the past 15 years I have stayed on average 5 to 10 nights a month at hotels. I can honestly say that I have never, in those 15 years, encountered such loud cleaning ladies. We were on the first floor and at about 8h, they would come in for the start of their day. Instead of walking towards each other to speak, they just yelled from one room across the other room. Every morning they would wake us up with non-stop shouting and laughing for about 45 minutes. Again, I want to specify that they were not even talking loud, they were SHOUTING at each other from room to room... This would last for about 1h till 9h00. 
RECEPTION: I know this is superficial but the reception staff looked very sloppy (belt was falling apart, broken name tag, ungroomed...). They were nice but it gave the impression that they don't care. At the end of the day, it doesn't make or break a stay but it doesn't give a great first impression. 
BREAKFAST: I really liked it. Yes it was crowded but there was a great variety and nothing ran out. We went twice at 9h and once at 7h. Never any lineup, and we never waited for a table. 
SHUTTLE/ACCES TO DOWNTOWN: During normal operating hours, it was fine. The shuttle was always on time. From the time you leave the hotel to when you get off downtown its about 20-25 minutes. At night, after 10h45, its a different story. We called just before entering the metro and still, it took 45 minutes for the shuttle to come. I wish they were more organized because even-though we were the first one at the stop, while waiting, more people came in and they had to send another shuttle as this one got full. Unfortunately, some rude people who arrived after everyone ran to it and were the first ones to jump in while the ones waiting for over half hour had to wait for another shuttle. As a suggestion, when people call to order the shuttle, they should take the name and make sure that those people gets in before those who did not call. 
At the end of the day, it was simply okay. I would probably book there again if I was desperate. But I would probably spend a bit more to get better.