Mine was tight to get on, but correctly snug when on.
I wear a XXL 509 so that's what I ordered, I could barely get it over my head and once I did it was super tight. I tried a XXXL and same thing, hurt like hell pulling it on. once it was on it was loose. for $400 I wasn't happy with the fit of either size and then when I broke out the scales and saw that Carbon was no lighter I sent it back.