I also use sandbells and like them a lot but those Dumbags look good to me as well. What I like about the sandbells is the reduced risk of injury. When they drop and fall on your foot, nothing happens (tried this out up to 12 lbs. – don’t have heavier ones). Since I like to play catch with them with my clients, it makes a great tool for those with grip issues or hand/eye coordination. It looks to me that the Dumbags could be employed in the same fashion.