Drilled my Tenacity Grit 35x4x40 (pin at 1 o'clock) with a 3/4" P4 hole as Canada has been slow to pass the 3oz side weight rule change. My goal with this ball was to have a stronger ball that I could use to slog through the track on ugly patterns (USBC's, Masters patterns)
Out of the box this ball was an absolute tank - really dull, early rolling and typically out of energy by the time it got to the pins. As much as I want to keep the ball at box finish for tournaments, it was too strong for me to keep the ball in front of me. I hit it with a 3k pad so that I could get it a little further down my lane and found it very effective on fresh in our challenge league which at the time was on 45' Route 66. This quarter we have been on 41' Beaten Path which has been very snappy off the back ends on fresh. I have since added polish (which I very rarely do) and love the reaction I see, giving me the traction I need up front, but still that smoother downlane shape that makes it easier for me to stay in the pocket. By the end of game 2, I typically have burnt up the heads and need to either take a step left or ball down to one of my midrange balls (Method or Cutting Edge Hybrid).
In terms of reaction, the Tenacity Grit is my second earliest rolling ball behind my Kingpin Max. The strong layout is a major factor, but it starts up sooner with less change of direction than I see out of my Conspiracy, Quantum Bias or Kingpin Rule. This type of reaction is what I look for on fresh oily lanes, where I want to read the lane sooner, maximize the help in the earlier parts of the lane and control the shapes I see down the lane whilst the back ends are still snappy.
I recommend this ball for bowlers bowling on slicker sport and challenge patterns. The Tenacity Grit will provide the early read and consistency to keep you in play, while the lanes are spotty. This type of reaction isn't very effective on most standard THS, but could be an option if the house is particularly slick of the bowler is of low track/high speed. The Tenacity Grit is my ball of choice for flat patterns and has earned itself a spot in my traveling tournament bag.