Thats interesting, Dave. I have not noticed this type of feed screw you mention. The few I have clearly cut a thinner chip and take longer to turn through the bore hole. Where I also have a very coarse version that hogs out a much thicker chip. The cutting power is noticeable between the two bits, but not that great. I find the gears on the machine make a huge difference in fatigue of the operator. Specifically the Boss Double Eagle and on my home made gear reduced machine.