Hi, I'm fairly new to sharpening. Following advice in this forum, I bought an Norton India two sided stone, and later an Arkansas Hard (white) stone. I've been improving and learning, and now want to buy one more final stone. I should mention that I am a home user, not a professional chef. My natural choice would be an Arkansas Black. However, as far as I understand, it's grit is around 4000. Ultra fine waterstone get to 6000 or even 8000. So, my question is: how meaningful is the difference between 4000 and 6000. Should I just buy a 6000 grit water stone and be done with it? Or is 4000 enough for my rather basic purposes?