How do precast concrete retaining walls compare to brick?

When comparing precast concrete retaining walls to brick, you'll need to consider several issues including the installation process and vulnerability to moisture.

Ease of Construction

One of your main concerns will be the procedure required to erect the retaining wall. The construction will be much easier using precast concrete. Laying brick is more labor intensive, and requires skill working with mortar whereas the wall can be constructed in one go with precast concrete.  

Moisture Protection

Precast concrete retaining walls get their strength from being able to remain watertight. The joins that remain when brick walls are built can leave it subject to movement and water ingress, which over time can affect the structural integrity.