John & Ron:
I had a little Drill Doctor once. I gave it to my BIL. Darex, the company that makes the Drill Doctor makes some really nice, very expensive drill and end mill sharpeners of which I don't have, but that's another story.
Once you become proficient at off hand sharpening (John, it's like sharpening a chain saw chain, practice, practice, practice), the Drill Doctor becomes unnecessary. All that's necessary is a 6 or 8" bench grinder, a wheel truing diamond dresser and a drill gage to set the included angle. The DD is nice for a touch up, but if you fracture the tip of the twist drill, it's much faster and easier to re-sharpen it by off hand grinding.
Interestingly, I always seem to be sharpening the drills for all the mechanics at my employers shop. I'm popular for that.