My 20k stone arrived yesterday and I lapped it with a 300 and 1000 diamond. I bought on eBay a Mastro Livi that came in with some chips on the front quarter of the blade and uneven bevel on the back quarter. I was able to hone the blade with my shapton 8k, 16k and 30k stones and get a pretty good even edge on it. Still, it wasn't really what I wanted. Took the 20k stone and lapped the Livi 5 times blade edge first. Much better. Then I put the stone under running water and lapped it 5 more times spine first. WOW! I tried the HHT and it sucked the hair against the blade and cut it. Then tried on my arm and cut hair half way up. Then to my face, don't even feel the blade cutting. I am a believer. Best stone I've used and I have used Norton, Shapton and a couple more I can't remember. Worth every penny. Will be dynamite for touch ups.