You sell a three-actuator system and a four-actuator D-Box system. What are the advantages and disadvantages?

Both configurations provide our range of motion feedback Up/down, left/right, front/back with intelligent vibrations. The three actuators system was originally designed for single chairs, while the four actuators systems are aimed to be integrated into massive single chairs and love seats/sofas. There are two types of actuators: 250lbs or 400 lbs capacity.