I won't claim to be as experienced in the MgR calculations here, but I think there's a big influence that depends on the variations in frame volume in the head, and where more mass is concentrated within the top half of the frame relative to other racquets. Two racquets can have the same SW and balance, but have different concentrations of mass distributed above the balance line. From my experience, the racquet acceleration process around the circular swing seems to interact with this mass topography, creating different somatosensory experiences throughout your swing. I can't break it down graphically, but I certainly do feel it. I would place the eZone 98 in that list of racquets that sometimes feel laggier than the SW and balance would suggest. SW is definitely part of the equation as well. There's also the matter of the volume of the beam, and where more volume is located, which and aerodynamics, which further complicates the picture.