NUCs build up more rapidly than packages and do not suffer the sudden drop in population (dwindling) associated with the aging process in packages. The population of the package dies off without the advantage of having a stockpile of young bees hatching off and replenishing the population.
NUCs are not as delicate as packages and do not require the careful handling associated with package bees.
Our NUCs are less likely to supercede their queen. She is already a functioning part of the hive. She has produced the brood that is in the NUC. It is already a fully operational beehive, only smaller.
NUCs do not require immediate installation relieving the urgency to immediately install in adverse weather conditions or at inopportune times as may be the case with package bees.
Remember, NUCs build up faster increasing the chances for a bigger honey crop!