Paris airport - 5 hour delay until next flight - should I go into the city for an hour or two?

Tuesday, I will be having a connecting flight at Charles de Gaulle International Airport in Paris, France. My next flight is 5 hours after I land. (It's to Vienna) Would it be an unwise idea to head to the inner city of Paris after I land...just for an hour or two. I hear it's 45 minutes to the city from the airport. Even taking a ride around Paris in the taxi would be great for me. Is it a bad idea to leave the airport?