mit4039094wrote a review of Castelli Gabba WS Men's Jersey on November 27, 2012
Jersey has its merits, but it's not as good as it's made out to be.
Two big problems. First, it really doesn't breathe all that well. The wind resistant fabric is on the back as well as the front, plus it has no zippered vents, unlike many wind jerseys. Plus, it wicks very poorly. Not as bad as a wetsuit, but heading in that direction. If you're a GC rider on Garmin Cervelo with zero mass in your upper body, maybe you can stay cool. Otherwise, maybe not.
Second, the jersey is very elastic, and that extends to the zipper backing as well. So trying to zip/unzip with one hand is very hard. Like pulling on a rubber band. And if you leave it more than 1/3 unzipped, it catches wind like a sail. 1/2 unzipped on a descent and it unzips itself to the bottom, then sticks, becoming a parachute.
So I find it's a great top layer when it's really cold. If you're like me, over one or two base layers/arm warmers, I'm comfortable into the low-30's. Get into the upper 40's and I start to feel really uncomfortable.
Quality and aesthetics are great, by the way. If you take it as a short sleeve jacket for very cold conditions, it's really nice.