I have used Go Industies mud flaps for over five years. Extremely well built and have anti-sail bars and weights. They look great and perform well. Not a single rock mark on any RV I pulled. I like my truck looking nice and the flaps hanging off the back bumper are not my cup of tea. I have these mounted low on purpose. They drag under rare conditions, but show no damage. Give them a good look.
http://www.autoanything.com/mud-flap...6A3727912.aspx