Noise reduction is an aerodynamic benefit
btw: VMCG doesn't necessarily become lower depends on what's written in the TCDS--no? as Chris Scott once 'schooled' me on the airbus and on that type as well as a Vmcg is fixed therefore it would be a benefit---on a new [with the appropriate data] Boeing No ---it can change with a DERATE!!!
unless you know everything about a type never second guess performance
and 150 knots is not the time to be in the charts
me haces muy cansado---ay