The most impressive thing about this jacket in my opinion is that it is insanely light and thus very packable. Many times when jackets claim to be packable they still feel bulky in a jersey pocket. With this jacket, you might not even notice that it is in your pocket!
I am 5'9" and about 190lbs (not small), as with all Castelli clothing, you should size up. I would normally order an XL (in Castelli), but for this I ordered a 2x. The 2x fits well, but it is a little loose while still maintaining the form. The reason I went with the 2x is that I foresee using this jacket most when I might have a long sleeve jersey, but need just a little more protection (more than a Gabba).
Castelli claims a small amount of waterproofing with the jacket, but it is definitely not a rain jacket. I would trust this if there was a little mist in the air, but for any real precipitation, you would need a real rain jacket.
I have 2 of these in different colors, a great option for very warm rides: seems to do best -- for me at least -- in the 75-90 degree range. (90+ I'm reaching for the Castelli Climber's A/C jersey or something similar.) Fabric is lightweight and stretchy, feels great against the skin. It's form-fitting without being a super tight race fight. (I'm 5'9" w/ a 40 chest and wear a L.) The zipper is very easy to navigate when lowering during climbs and pulling back up for descents. The lack of design/branding is a big plus in my book, makes it easy to combine with various different shorts regardless of brand. Keep in mind that the white version is a bit transparent; I think the main product photo for the white ("ivory") is very accurate in this regard.
My only complaint is about the rear lower hem. It doesn't seem to stay flat, kind of folds up under itself during rides. Not a major complaint; not worth taking off a star, and might be due to my size. But something I've noticed in comparison to other jerseys I have from Giordana and Assos that don't have this problem. Regardless, fills in well for the very warm (but not hot) riding range.
Need a jersey for hot weather riding in central TX. This A/C jersey is form-fitting without feeling constrictive; length is just right (I'm 5'9" w/ 40 chest and wear a L); pockets are relatively tight despite being an ultralight jersey. Overall excellent performance in hot (85+ degree) weather. Keep in mind it's very transparent, as expected with a jersey like this. My only minor complaint is that the sleeve length is a little long, but that might just be my sizing.
I've been using these Castelli arm sleeves for years. I am happy to minimize the amount of sunscreen I use on my body while maintaining good UVA protection. In addition, I am able to use these even in the hottest weather as the sweat on them wicks off at speed and has a decent cooling effect. The only think about them is the price and the fit - it's tough getting the upper arm attachment flat and comfortable at tiimes and the wrist area can sometimes be loose.
