Due to various influences (including reading this site) I have begun commuting to work on my bike several times a week.  I am commuting on my only bike which is a 2007 Lemond Versailles bought to keep up with my cycling friends on group rides.

I am considering buying a less expensive bike to avoid punishing my Lemond too much and as a general excuse to get another bike.  Some people on this site seem to like the aluminum Cannondale bikes and I wouldn't mind getting an aluminum bike.

In looking at the bikes, I noticed that Cannondale still has a level top tube while most of the other bikes now have a sloping top tube.  Can someone explain the difference?  Also, I saw a specialized Allez at the bike shop that looked extremely intriguing.