I was just speaking from personal experience. Using a drill caused the holes to be off center slightly. The finally hole was the correct diameter, but they just weren't centered. I bought a Fox reamer and it was the best $10 purchase I ever made. I could cut a hole in a prop in 15 seconds without having to bother fiddling around with a drill. Every prop I've ever cut with the reamer has turned out perfectly. I'm sure if you are careful and have really good equipment than a drillpress will work (although I still believe it will not have a near 100% succes rate like a reamer would). Testing a drill press a $2.50 10x6 prop is really not a big deal, but when you start cutting $12-$40 props you want to be sure you'll get good results.