Data, and some opinion!
There is a lot of talk about sizing with Castelli. Here are my measurements: 6'2" 190lbs. 42L jacket, 34x34 pant size. I ordered XL in this jersey and L in the matching bibs. The fit is aero. The fit is perfect. Keep in mind that Castelli jerseys are cut for a riding position. The chamois is very comfortable for weekday 30-40 miles. Don't know if I would wear out for 60-75 on the weekend. Also, OK with the compression. Really nice looking.