It really depends on what you want out of a sharpener and somewhat on your skill.
WSKO is pretty fast to fix neglected edges. It's incredibly fast compared to hand sharpening. The stock belts give you a decent range of grits including a super duper polishing belt if you want to show off. I like some of the other available belts better, but it's not a huge consideration.
Because it's a fast power tool, you can do damage pretty quickly too. It's very common for people to put a notch into the heel of their blade because there's a tendency to let it sit on that spot for a moment at the beginning of each stroke. This can be bad, so you definitely have to pay attention to what you are doing. I suggest starting with knives that you don't care about at all. You might hurt some of them while learning.
To be fair, I don't use the included angle guide, so my perspective is a little odd on this. I use it more like a little tiny belt sander. The guide can make some of these effects more pronounced based on the videos I've seen and what I've read others say. I've never used it.
Deburring properly on a WSKO is very difficult. In fact I would say it's nearly impossible. You really need a final deburring step of some sort to augment your setup. Maybe a strop, or a fine stone. I've had great luck with the sharpmaker as a deburring step after the WSKO.
Brian.
