There is a good discussion on lowering springs and pro/con of an LSD here:
My opinion is, that I wouldn’t want to daily drive my sirion with its LSD and suspension as it is day to day on the streets. I would look elsewhere first for driving/handling performance on the streets before getting an LSD. Shocks, Springs, suspension Bushes, Sway bar(s), chassis bracing, changing the drivers seat position can change the feel, shifter bushes.
Other gear-related benefits would be a change to the gearset or final drive. For a street driven car you may not want to go too low a final drive as you’ll be at higher rpm when cruising at 100km/h. But there are a few options out there, and let’s be honest the factory gearing is aimed at economy.