If you have electronic damping control (ie dial-in suspension stiffness) then your soggy handling is probably either due to the suspension struts themselves being worn out, or maybe just the EDC control being inoperative - the default setting will be the softest one. Each strut has a little servo motor which winds the valve settings in or out. I understand that many people just elect to replace with standard high quality struts (Boge, Bilstein etc)and give the electronic stuff the flick.