The more acute the angle the better it'll cut, but if you make it too acute it'll start rolling or chipping on you. The best angle for you depends on what you use the knife for -- if you cut wire with it you'll need a much more obtuse angle than if you only use it on soft materials like wood. It also depends on the steel and heat-treat; some knives can take a more acute angle than others.
Knives almost always come with very obtuse angles so the manufacturers don't get returns from customers complaining the edge is damaged. The way to find the best angle for you is to keep making it more and more acute until it starts getting damaged, then back off a little. It makes sense to keep one or two knives with obtuse angles for heavy work and keep others razor sharp and avoid using them for anything that would damage that delicate razor edge.
This ought to be in the FAQ ... maybe it is; I haven't looked lately.
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-Cougar Allen :{)
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This post is not merely the author's opinions; it is the trrrrrruth. This post is intended to cause dissension and unrest and upset people, and ultimately drive them mad. Please do not misinterpret my intentions in posting this.