Do yourself a favour.........get an Edgepro Apex.
Great system, american made (I'm not American, but I love American tools), and easy to use.
I toyed with stones but there's always the issue of holding the same knife angle while you sharpen. The Edgepro is just awesome and so easy and fast.
I had blunt knives I have used for 4 years, and I sharpened a whole set of 5 knives in about 1 hour, first time I had ever used the Edgepro.
The more proficient you get the faster you get.
Sure it's not cheap, but you can set the bevel angle you need, normally 21 deg for German, and around 18deg for Japanese knives (but this varies), and you can use the supplied stones to set the bevel and then polish the edge.
I love it, and my kitchen knives are scary sharp now. So much so I took the tip of a finger off and didn't even know it, until there was blood on eveything on the kitchen sink! My wife loves the sharp knives now, although she is very weary of them!!!!
I have no affiliation with Edgepro, or any Edgepro reseller or any other commercial arrangement or friendship with Edgepro, but I emailed Ben Dale who owns the company, just before I bought one, and he emailed me right back with great advice.
He's a nice guy with a great product.
For knives, you won't need the Apex 4 (with all the grit stones), you will only probably need a 220grit, 320 grit and the 600grit as well as the ceramic, unless you have really expensive Japanese knives that need higher grades.
Check out his videos on Youtube......search for Edgepro......
Honestly, you'll never buy another kife sharpener, and it does hunting knifes, serrated knives, eveything. They say it can do razors but I don't think the angle adjustment gets flat enough, and also the grit grades are probably not high enough, but I've never tried it.