BOS is usually pretty good about bag rules. I few last week out of BOS with a 72 lb. monster full of Christmas presents. I got screwed bad once this year on a return leg of of London City airport on KLM Cityhopper flying LCY-AMS-BOS b/c of the KL Cityhopper limit (20 kl). I told the KL agent that I was going international out of AMS but she said on KL that the limit is 20 kilos regardless. In an instance of panic, I started flashing my NW elite card while trying to be nice but acted as if she had never seen one and said that that was NW and I was flying KL. After talking to her supervisor he allowed the bag. But then in a seperate issue, b/c the Fokker was overloaded and overweight, and I was the last pax to check-in for the flight, they tried to bump me on boarding in exchange for a 50 Euro voucher on KL. Note here that I had a confirmed seat assignment. Again, the supervisor showed up and after telling him that I had an international connection in AMS, he bumped a domestic pax instead.