The problem I have with some of the changes brought over from NW is the box we fly in has become very small. So small in fact that pilots have to fly outside that box or the operation would come to a halt. What is strange is hearing a pirep now like "Delta XXX had a 15knot gain of airspeed at 400 feet". Under the new rules that is a mandatory go around. Under those rules we have one to two days a month in the winter where every flight into JFK should divert. There are several other examples of this. Changing wording from "should be considered " to mandatory simply puts most pilots in violation of company procedures in day to day ops. That should not be the case.