Even though El Segundo is a small city location is extremely important from the standpoint of owning real estate. If a property is too close the airport it is loud, if a property is too close to Chevron there are fumes, if you are in the north west quadrant it sometimes smells, and if you are too close to Sepulveda there is more crime.
The "A" locations are between Grand Ave to the south, Palm Ave to the north, Hillcrest to the west, and California to the east. There are a few exceptions to the east, however in general this is a good rule of thumb.