I just got mine today. It works very well. You just center the rings in the holes. I used clear rings, and there is no noticeable roll off. I had to move one of the corner ball spots just a tiny bit because I didn't have it centered well enough, but now that that's done, it works well and there are no gaps between any balls.
I will try the included dots, and also some doughnut print ones I got. There is a blue doughnut with white icing that I think may look quite nice on tournament blue.