If you do any group rides, or just like to ride long and far solo go with the Allez. You'll appreciated the aerodynamic benefits of being able to ride lower and multiple hand positions.

The Sirrus, while a very capable bike, is a bike that does everything just okay--riding around town, getting groceries, towing your three-year old, even group rides, but it does none of them great. So you have to decide what you really want: a machine that does one thing great--going fast, or a machine that does a lot of things just okay.