It depends on the artwork. Line work, portraits and heraldry read well in relief, where varying depth catches the light. Flags, club logos and anything that relies on specific colours need printing instead, because relief carries no colour of its own. Some makers combine both on opposite faces of the same blank.
What material works best for a coin blank?
How deep can relief go on a brass coin?
What size are most coin blanks?
Do finished coins need anything after the machine?