Rome republican

Coming from the US 21st century point of view, we often have very fixed ideas about the words “republic” and “imperial”. We tend to focus on the ideological differences and conclude that a Republic is fair, just and upheld by a social contract, while an imperial system by nature is harsh, brutal and, ultimately, a tyranny, but do you feel this was the case in Ancient Rome?

Based on your readings on both the Roman Republic and the Roman Empire, which do you feel was the superior form of government in regard to its efficiency and functionality, leadership, treatment of citizens, economics, creativity and progress, etc., and why?