I don't spend enough time on my knives. I'd never use a powered sharpener, but I do have a few devices (Lansky, etc) that I'll use when something is really hurting. Shop tools are easy as usually there are only straight edges. Knives really take a skill set that is a level up. If I used knives for more than opening boxes or chopping up some taters, I'd certainly invest in learning the skills.