What beans are better - Arabica or Robusta?

Arabica beans are usually more expensive, because of their better flavor and aromatic characteristics as compared to Robusta beans. They contain half the caffeine of the Robusta beans.

Arabica have a wider taste/aroma spectrum than Robusta beans.

Robusta produce more crema in the cup. It's taste is a bit stronger than Arbica's, and the crema is foamier.