I try and shoot the first five super clean all A's. then after that I go faster till the wheels fall off. Then pull it back together slowing down just a bit. To be honest I have a hit factor calculator
I use on all drills and my wheels falling off produce the best hit factors. Lots of times I will throw in a reload and put two back too back. I think if you are a USPSA shooter this is one if the best drills you can practice. Transitions eat lots if time.