You must remember that surface is key. My night hawk and x are drilled the same, and my X is 2500 grit, and the nh is 4000 with polish. Same basic ball with same layout, and there is enough separation to have both, for me. The nh bounces a bit harder off the spot than the X.
Now when the DCT pearl comes out, I'm going to put that on top and put my On at 2000, and have the same layout. Then ball down to a Covert with the pin down, soni don't get the ball jackknifing off the friction.