I have worked in both a meat packing plant and at a retail meat store so I'm pretty good at sharpening knives but to do it right it takes a long time when you have quite a number of knives to do. I have tried a few different brands of knife sharpeners and found they either didn't get the knife very sharp or they didn't have enough power.
I found this one at Fleet Farm and it has worked great. It' fast and when your done you could shave with the knife. I cost about $120 and worth it in my opinion.
It only takes about 1 minute per knife the first time to get the bevel correct then after that it's only 20 - 30 seconds when you have to re-sharpen.
I just have to make sure to tell the wife when I do it so she doesn't cut herself when the knife goes through so easy.