I want at least one of every kind of bike. Except maybe BMX, but I'm biased there.
I do know that I'm faster now on my road bike than I ever was on hybrids, but on the other hand, this could be a training thing, as once I got my road bike I started cycling more on the weekends, for pleasure, etcetera, so my biking muscles are simply stronger than when I was just commuting.
I think I will go back to using my Bridgestone (old hybrid) once I get new cables installed. That said, the only advantage it has over the road bike is that it's worth a lot less so I don't mind beating it up.