If you’re considering an electric drill bit sharpener that allows you to get the most out of your old drill bits, the Drill Doctor 750X deserves a close look. It works with bit sizes from 3/32 inch up ...

I've been thinking about buying one of these but I don't know if they are just a gimmick. Also, if they genuinely work well how good do your bits need to be in the first place to be worth sharpening?