Soft eyes are preferable for general hauling, and will collapse to fit through conduits and rollers. A thimble will protect the eye from wear and tear, but will also not allow the eye to collapse.
Thimbles should be used in permanent or semi-permanent load restraint or load sharing applications where some load will be applied to the grip for extended periods of time, or where the eye will potentially rub against another hard surface.
It is important to note that a cable grip should never be used as a permanent termination, nor should a hauling grip be left attached and at load for extended periods of time during a haul.