It would be annoying as heck to see the thing if it is in the line of sight, the thing does NOT blend. If it is clear then that helps alot right there.
But I cannot fathom that if you happened to have a shot at a ball sitting on the rack that and you have to draw the cueball along the path of the racking paper that it would not effect the shot. Plus supposedly slow rolls are affected, they have tested that.
All of that said the matches I watched with it had the 9 squatting, not moving in the slightest, and that is nice to see.