I have a Assos medium jacket that fits perfectly. The jacket made me a fan of Assos products. The medium version of this jersey was too tight and too short. I'm 6' tall, long torso and a 38" chest. The large version fits great even though tight. The sleeves are tight on my arms which could be a problem for a more muscular guy. But I love the jersey. It feels and looks great.
I ordered a medium, my usual size, and couldn't believe how tight and uncomfortable this Jersey was and how thin it is ..especially in the torso area. I mean most of it, to me, seems like way over-priced material that is almost made out of white leg stockings! I guess I just don't get it. Additionally, I am only 150 pounds - so a medium should fit, feel, and look better in my opinion. And as thin as it is I don't see how the SPF rating it states it has protects you. I have returned it and am getting a Garneau jersey instead.
I love Assos bibs & shorts, but I've had a hard time keeping one of their jerseys. I wanted the white version of this jersey for summer >80F. White clothing in desert heat works great for temp management. But this jersey fit a little smaller than expected and was much too translucent for the entire abdomen - requiring a base layer and defeating the purpose of having white. The material also seemed to be less robust and prone to premature wear, but I didn't end up testing that. Ended up returning and going with the Giordana FR-C Pro which has super strong, thin, lightweight material and the fit and compression are perfect for me.
I'm not one to gush over clothing, but I really like this jersey. It fits well, I like the color and that it is a solid color rather than the many busy,multi-colored "event" jerseys I own. I like the slightly longer sleeve and the way the sleeve ends without a band at the end. I've received numerous compliments on the jersey from riding friends and from strangers on the road! (That's never happened before).