I used to wear cotton suits when traveling for business in the South in the 80's. They just looked right. You looked like you were making an effort to fit in and not trying to be a City Slicker from New York City in the navy pinstripe. These days I like cotton for the same reason as Parker, it has a casual vibe. Similar to linen. In this day and age of casual dress cotton or linen make smart, choices for jackets except in very traditional, dressy settings. I wa sjust looking at an off white/cream/light beige suit yesterday (cotton). I could mix and match the pants and jackets with polo shirts, jeans or dress it up with a crisp blue shirt and tie.