Core Velocity system is great if you know how to use it. Bought one a couple of years ago. Had little in the way of instruction at the time & really wasn't very helpful. Lantz now has much more information & drills available. Read up on his site, one thing he mentions frequently is the "butterfly effect". Got to identify the area that causes issues later in the delivery. After analysis and identification my son is making tremendous progress. Bottom line it's not something you can just strap on and see immediate results if you don't know what you're doing (IMO). On the other hand if you fully educate yourself on the system it is a tremendous asset.