Not sure how it is in the US but First class at CDG, LHR, and FRA has a separate security line, preferred boarding, and a greater luggage/carryon allowance. You

Not sure how it is in the US but First class at CDG, LHR, and FRA has a separate security line, preferred boarding, and a greater luggage/carryon allowance. You are served champagne and appetizers, given a hot towel and slippers for the flight. While everyone down the back is rushing to clear security, check-in, get a sit and find space for their carryon you are on the way to a second cocktail. If you can afford it or get it it's a really great way to fly.