I totally geeked out on these Nano Hone stones. Since last month, I’ve picked up the #200, #400, and the ridiculously expensive NL8.
I also have Shapton Glass 220; side by side, the NH is a more pleasant feeling stone. It’s hard to characterize but the SG220 feels more “gritty,” which sounds ridiculous for a coarse stone comparison. Still it’s relatively more gritty feeling than the NH200. This matters re: single bevels mainly. I can’t tell if it’s faster so I’m saying they’re equally effective. Given thickness of NH usable stone is probably double that of the Shapton. Dishing rate is not discernibly better. Whenever I have to replace a 200 class coarse stone, I’ll buy another Nano Hone. I have used both for thinning projects for iron clad and stainless clad with Shiro2, Blue2, SG2, ginsanko, super blue, and AEB-L. Seems like they’re both appropriate for the full spectrum of mainstream steel configurations (can’t speak to the “exotics,” with super wear resistance / high carbides).
The NH400 is a great stone. I do believe it’s worth the investment to get both the 200 and 400 if you’re in need of coarse stones. Saves time. Stretches life of the stones. Compared to my SG500, I can’t honestly say I prefer one or the other. SG500 is a really good stone! The SG500 feels smoother (of course!) and it shows more black swarf so SG500 might actually be faster, I don’t know. Either way, stepping from here to the NH1000 works nicely. I should mention my NH1k has been used a LOT. It’s getting smaller. Although it still has a lot of miles ahead, it is not miraculous in terms of wear rate.
Of the 4 NH stones I have, my experience with them is that they do carry the same characteristics across their respective grit classes. There is a Nano Hone Experience and I think they make an effective, convenient, versatile, relatively compact set. Comparable but different than Shapton Glass. Biggest advantage for SG is portability. Biggest advantage for NH is overall experience (effectiveness, quality of construction).
I don’t have any proof yet whether getting the NL8 is totally crazy. It seems like as long as it lasts about 2yrs (for me and my heavy usage) then it would actually begin being more economical than replacing Atoma 140’s. It’s very clear that compared to an A140, the NL8 performs much much better. Laps faster, zero stick/suck! And the really really huge advantage of NL8 is the finish left on the stone. It’s a very nicely conditioned surface across every stone I’ve lapped (already I’ve tested quite a few). I don’t regret purchasing this item.
Overall I’ve had awesome experiences with Nano Hone, Shapton Glass, and Gesshin Stones. Better than several other options we currently use or have used in the past. In my opinion, these 3 embody the best synthetic sharpening stones currently available.