Approaches to a mass balanced flexure gimbal assembly for controlling the sway mode of the loadbeam portion of the suspension of a head gimbal assembly (HGA) of a hard-disk drive (HDD). The sway mode of concern is that which is excited when a head slider is actuated by a plurality of piezo actuation devices of a secondary actuation system. A suspension includes a mass attached to the suspension flexure and configured for balancing a moment force about the gimbal, about which a slider rotates when microactuated. The mass is located on the side of the slider opposing the side on which the piezo actuation devices are mounted, to counteract the mass of the piezo devices.