I have the previous generation of Perfecto jerseys, and have added the newer updated version over the past two winters. I love both of them. I have found that the newer versions are a little more airtight. These jerseys block the wind really well. I stay warm, and just as importantly, I stay dry. I have yet to ride through rain wearing a Perfecto, but it does well in managing the sweat I create during the two hour rides I usually do. Even if the temperatures rise ten or more degrees from the beginning to the end of 35 miles, I can adjust the vent zippers, and also unzip a little more on the main to adjust for the warmth and stay comfortable. I have worn the Perfecto jersey in temperature from the high 40s to the lower 70s. I have never arrived home complaining about comfort. It lives up to its name!
Have not worn on the bike yet. When I tried it on was actually a good fit except the arms are a little tight at the elbows. I purchased a large and it is just big enough. I am 5'9" 138lb so not your petite cyclist which this brand is designed for.