When is it better for a man to shorten his hair than to shave it?

Shaving is generally better than shortening, except for the Mutamatti' (pilgrim performing Hajj At-Tamattu') after his 'Umrah. For him, the prescribed act is to shorten his hair so that shaving can be done upon exiting the state of Ihram for Hajj. This is supported by what Ibn Qudamah said: "It is recommended for the Mutamatti' upon exiting the state of Ihram from his 'Umrah to shorten his hair, so that shaving is reserved for Hajj." He cited the saying of Ahmad and the action of the Prophet, peace and blessings be upon him, who commanded his companions to shorten their hair. However, if the Mutamatti' shaves, it is permissible.