I have a 560 SEL that still have the SLS system. Too much money and time spent but the car still handle bad. My Euro 500 SEL did not have the SLS system ( thank god. Anyway I would not have bought it if it did have the SLS system) and it ride and drive great. Your best bit is to check the subframe mounts, check the springs and ensure that they are good. Re-installing the system is not going to make the car handle better. Also check the rubber on the top of the springs and make sure it is good. Worest case is new springs, new subframe mounts which probably cost half of the SLS pump alone.