These sort of contradictions make him interesting--he's a basically kind-hearted man who also has absolutely no trouble committing violence, but neither does he seem to get a sadistic pleasure out of violence. The scene with Cicero was surprising and good because of how, in the midst of this very solemn and final and political thing Pullo was doing, he was also thinking about bringing a nice gift to his wife--and let's not forget that he also turned the whole occasion of having to go commit a political assassination into an opportunity for a picnic in the country.