SCARAs are generally faster and cleaner than comparable Cartesian robot systems. Their single pedestal mount requires a small footprint and provides an easy, unhindered form of mounting. On the other hand, SCARAs can be more expensive than comparable Cartesian systems and the controlling software requires inverse kinematics for linear interpolated moves. This software typically comes with the SCARA though and is usually transparent to the end-user.
Most SCARA robots are based on serial architectures, which means that the first motor should carry all other motors. There also exists a so-called double-arm SCARA robot architecture, in which two of the motors are fixed at the base. The first such robot was commercialized by Mitsubishi Electric. Another example of a dual-arm SCARA robot is Mecademic's DexTAR educational robot.