As others reviews, is not that easy to use as STP, if you combine this with a Willie or Miper it would be the best.
The curve of this product is amazing, the problem is no just stp use (a lot back flow), when you use it with your harness it won't hold it, all the time I have to move it because it tends to fall towards out/front to the harness (if that make sense).
Please consider fusion this design with Willie or Miper, please please please.