It's funny that prior to the cronograph being in everyone's tackle box, people just new when a bow was slow, medium, or fast. Now we need numbers to tell us; new age I suppose.
There are ways of maximizing performance as well, and those include, but are certainly not limited to, good consistent form, and a pull through release on each shot. Consistency creates accuracy, and accuracy kills.
Don't get too enamored with numbers, just make sure you are doing all you can to maximize the performance through consistency in your form.