The family of carbon nanostructures has attracted great interest for their unique physico-chemical properties. The importance of their discovery was recognized with the Nobel Prize in Chemistry in 1996 for the fullerenes and in Physics in 2010 for graphene. There is a wide morphological and structural diversity within carbon nanomaterials that includes also dots, nanotubes, nanohorns, nano-onions, and so on. Their added value is manifest especially in composite materials, for applications that span from sensing and medicine, to energy, construction and the aerospace industries. However, which nanocarbon is the best one to attain functional composites is a question that in most cases doesn't find a straigthforward answer. In this presentation, Silvia Marchesan will highlight recent studies where nanocarbon morphology exerted important effects on the properties and performance of the resulting composites, or even hybrid materials - when new properties emerged.