I think putting the EMBs on the BOS-LGA leg is a good move. The aircraft is very comfortable and is now almost as reliable as an Airbus. It doesn't have the carry on bag space of an Airbus, but with the low load factors the bags that shouldn't be too big of a problem. One big difference wiht US vs. DL on this route is that DL will operate with a contract carrier and US will be mainline.