One of the leaders of the Rebel Alliance, Mon Mothma, admitted when learning this that it would pose a dilemma if the Rebel Alliance did manage to capture one intact: they wouldn't have enough personnel to operate it. In large part due to their immense size, Super Star Destroyers required a crew of at least 280,000 to operate.
In at least one ship classification system, SSDs were regarded as large enough to be counted as space stations rather than regular starships. All the known models were at least several kilometers long in order to support their increasingly heavy power generators and armaments. The term 'Super Star Destroyer' described some of the largest warships ever designed and fielded, and covered various warship classes that served primarily as command ships.
