I'm evaluating the options ahead of me for sharpening my knives, and am keenly interested in the ease (of learning) and results-repeatability afforded by the Edge Pro system. My question, then, is how long can stones last in the EP's size? I'm considering getting the Chosera package. Contrary to popular belief, I don't actually prepare kaiseki feasts every other night, so my knives aren't really getting used that much. Let's assume for a moment that I clean up the edges of my two or three main carbon knives on an Idahone every use, and polish them with the finer grades once a month or so. How long can I expect the finer Choseras to last?