Corner balancing is adjusting the weight distribution of the car evenly between the LF/RR and the RF/LR. Its for handling purposes, mainly for track cars. A good driver can tell if its 5% and less off.
If you are just driving the car on the streets and dont plan on taking it on a track then dont bother.
Not too many shops have scales for corner balancing, the dealer DEF doesnt.

and pmed....