The 3 stone system is the way to go. And as you already know the proper, consistant sharpening angle is of the utmost importance.
But when you say "factory" edge, what are you refering to? Some knives have a hollow ground edge, and once that edge bevel gets worn down after repeated sharpenings then I don't how you'd get it like that again without a machine.
Personally I don't like factory edges, because for me the edge bevel angle is too steep. They cut fine when your blade is close to 90 degrees to the cutting surface, but if you lay the knife flatter they don't cut as well, and because of the steep bevel angle, you will have to put the knife on a stone a lot sooner to regrind the edge bevel.
I will take a brand new knife and spend a good half hour with it on a series of stones to get the edge bevel where I like it, which is a much less steep angle than the factory edge. Once it's sharp, I finish it off on a leather strop to polish the edge. When an edge is prepared this way (on a high grade steel hunting knife), and you don't abuse it, you can do a lot with it before you need to touch it up again, and by touch up I mean something as simple as a leather strop, or maybe a little honing on very hard Arkansas stone, which basically just polishes the steel. After quite a few touch ups, or if the edge gets chippped, dented or otherwise abused, then you need to sit down with the stones again and regrind the edge again to regain the right edge bevel. I sharpen everything this way, from knives to axes and even machetes. A cutting tool of any sort that's sharpened in this fashion is much easier to work with and is a joy to use.
Hand sharpening knives is a time consuming activity, but it's the only really good way to get a knife extremely sharp, and with stones you will not wear the knife out near as fast as you will with a machine. I would never take a good quality hunting knife and put it on a machine sharpener! It's sacrilegious!
