not questioning your results, just clarifying one point for those who are newer at heat treating. Sub zero is not cold enough for full conversion of retained austenite with this group of steels. You need full cryo. Well, you need to get last -140f, which sub zero does not. Your testing confirms that heat treating must be tailored to the application. There are advantages/disadvantages to high and low temper. High temper has better wear resistance at the expense of some toughness. I make mostly kitchen knives and thin slicers, where the increased toughness and smaller carbides are an advantage. Chris is using an application where wear resistance is more important. Heat treat to your application.