I ride them all... and my road bike idles at speeds I consider decent for some of my other bikes.
It is lighter, is geared higher, has much lower rolling resistance, and is more aero which allows me to ride at much higher speeds while being more efficient.
Conversely... I have bikes that don't look fast that are much faster than appearance would suggest.
Strip all the luggage off this little guy and drop the bars to a more aero position and you have a pretty fast package.