Drill Doctor is OK for the convenience. Drill Doctor reccommends turning the stone to even out the wear. Be careful taking the stone off as there is no way to reset the depth (unless you measure it before you take it off, or make some kind of gage to duplicate the factory setting) of the wheel on the shaft and this will affect the point splitting feature. I tuned my wheel over after a few years use and had to trial-and-error set up the wheel again so the splits would come out centered on the point. Otherwise it either over or under cuts the split.
DD is good for general purpose sharpening. Way under kill for big drill bits and not really precise enough for super accurate work. If you drill a lot of one size hole (#31, for example) just order them by the dozen from MSC, and toss them when they get worn.