I finally broke down and bought a good winter cycling jacket and man am I glad I did? This is the single best piece of cycling apparel I own, I love it. Fit is great, I bought an XL and I am 5'10" 175lbs, perfect fit. I only wear a wool long sleeve base layer under it from 0 degs and up. If it gets above 50 deg I only use a thin short sleeved base layer. Its pretty water proof too. The vents work well at the front.
Best of all its a really sharp looking jacket!! I also bought the neoprene Castelli gloves and Sottile jacket and they are the perfect compliment for my winter riding here on the wet West Coast.