I carry one in the bag now (it might replace grids for putting eventually). I use it for shots i don't want a KC to hyzer out too early, or a grid/dx to fly too straight. The McPros are my bread and butter for either a two-angle going straight with slight fade, or just a power shot straight. If I don't want a grid to flip on the approach, I'm using a McPro.
They do pop up flat really nicely with a two-angle throw