My Univega road bike is aluminum. The difference between it and a Cannondale is tube size. Smaller diameter tubed frames like mine have more flex to them-not as whippy like the old Alan frames that were glued together, but far more comfortable than the Cannondale in my experience.

The Specialized sounds like a good bike for what you want. If you haven't used them before, I also recommend step-in pedals. I have those on both my bikes. Mine are Shimano compatible. I got one set from Bike Nashbar at a pretty cheap price.

I have Shimano shoes as well-mine look like low cut hiking shoes with a rugged sole on them. A major improvement over my old Duegi road shoes with the big cleat on the bottom that made them impossible to walk around in.