This allows you for a full range motion squat, and still have the safety bars to catch the weights. (bodybuildingforyou.com)
If you do it regularly, you will be able to do the full range motions easier. (abmachinesguide.com)
The free range motion however gives you complete head movement even across its sharp turns and barrel rolls which can get pretty hectic on the eyes after a short time. (respawnpoint.org)