Compared to Samus's missiles, the Mii Gunner's homing missiles have far more accurate tracking, while the super missiles deal more knockback and have less starting and ending lag.
In Ultimate, the normal missiles have received a buff to their travel speed, but their homing ability has been greatly nerfed. However, both types of missiles have been made stronger and less laggy, while Super missiles are now able to KO earlier than before.
Special Move customization was added in Super Smash Bros. 4. These are the variations: