I have a Drill Doctor, and it works pretty well, but I generally just freehand grind, it's way faster. Besides taking a fair amount of time to set up, Drill Doctors only handle relatively smallish bits which are more economically just replaced.
Lisle makes, or made a really nice sharpener, and I'd let one follow me home for the right price. mrpete222 did a series on refurbishing one of these a while back
I have a lisle one, I need to get it off the shelf and set up, I have a drill doctor that I used for a while til the novelty wore off, have tried to sell it at a few garage sales and nobody even asks about it. I even have the VHS tape that came with it to tell about it, that has never been played
I have something big leaving my attached garage, (what is leaving, isn't automotive in nature) I am getting 2 things in its place that won't quite take up all the space it has occupied for the last several years, so maybe I'll have room to actually set it up.
Both things I'm getting will be easier to move around than what's leaving.
Gonna have to find some goodies to make me a stand to mount the Lisle drill bit machine onto at that point.
unless I can find a bench grinder stand with a dead grinder attached, somehow.