In my limited experience I've always felt Cannondale bikes to be overly rigid with an annoying buzzy feel -- the kind of harshness that can't be remedied with fatter tires.

I think what you've experienced is a combination of frame material, geometry and fit. Each contributes to the entire ride experience, and you simply enjoyed the blend.

But what do I know? I'm a steel framed, 72 degree head tube kinda guy. Twitchy handling, buzzy aluminum bikes have never appealed to me. Welcome to the comfortable side of cycling.

-Kedosto