Tonight was my first test of the new bike in the rain... full coverage fenders are the only way to go, I waterproofed my spd shoes last night, and rarely leave home without my rain gear packed... and installed Kool Stops when I built up the bike.
Since it was cool today I wore my waterproof shell jacket over it's base fleece so was dry and toasty when the temps dropped and the rain started falling.
Another thing I like in a commuter / rain bike is a comfortable ride and the ability to roll through bumps and potholes as when it is raining it gets harder to know if it that puddle is hiding a bike swallowing crevasse.