How efficient are child blueprints?

How efficient are child blueprints?

I’m not 100% sure on how the pillar of inheritance works with UE4 and I’m wondering if it’s more efficient to make a parent class blueprint for a set of functions and a child blueprint containing unique data, or is it the same as just creating the same functions within each individual ‘unique data’ blueprint?

I would assume by using parents and child blueprints you have the benefit of easily changing dozens of actions by modifying the parent.