Over all, Id say that is true.
When Iv been over seas (I'm american) I really noticed the difference.
Sure there are beautiful women both places, but European woman just seem to take better care of themselves and dress nicer when out.
When recently in Rome, I could spot american women from a distance, normaly chubby, sweat pants, T-shirt and hair ratted up in a hat or something, just plain sloppy. The Europeans where dress to kill and had great hair and makeup all the time.
This last trip really reenforced that opion. That picture illistrates it well.