I use the Sharpmaker and bought the extra sharpening rods. I use it with d2, s30v, and s35vn without problems. It's best to not let them get really dull. It works great for normal use. I'm sure there are better systems but the Sharpmaker is pretty to use.
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The Spyderco Sharpmaker does everything I need to sharpen my knives. It’s easy to use, keeps the angle perfectly, and makes my knife razor sharp in no time. Also great for a quick touch up. I don’t like to let my knives get dull.