I own a bunch of body bars (12 lbs. through 36 lbs.) and use them a lot if I'm doing higher rep workouts like The Firm, Les Mills Pump, Cathe's Power Hour/Muscular Endurance and Flex Fuel. They are quick to swap out. I'm glad I have them.
I use my Body Bars all the time. I bought them years back, when they first came out, and use the 12 and 15 pound bars the most. I have them ranging from 9 to 25 pounds. I use them for Les Mills workouts, for Cathe's workouts, and others.
I have 7 or 8 body bars of various weights and use them all the time. I don't have any body bar workouts but use it for all my other workouts in place of barbells. Really love them.