We also flew to Boston before Christmas for a weekend getaway. It was first tone at this airport. As the OP I was surprised to see how AC's gates are isolated from the rest of the terminal. We were looking forward to go to the US Airways lounge. To our surprise we were told that our gates were on the other end of the terminal. We walked over there and inquired about the AC terminal. TSA agents told us we could go to the other area to eat or go to the lounge and then come back. They were actually nice. We did so and had sea food and then headed to the lounge which was empty. Then went to our gate without any hassle while going through security.