Hi, Peter - I recognize some of the language in the ad copy (I realize you didn't write it) as starting as long back as DMT ("let the diamond do the work and use only light pressure".
it's not really necessary to do that, it's other materials other than hardened steel that will pull the diamonds free quickly, but I could be underestimating how much pressure some folks may apply.
What the pattern suggested to me is the stones you have and the stones sold under the same brand are coming from the same origin as trend, which ultimately is a chinese manufactured stone. People will ask varying prices for them. Cosman, who I don't follow but looked up the diamond hone, has an ask of $140 USD. i think that's in poor taste, but it's my opinion.
Changes in the distribution system put you in a tough spot - if you have a buyer who is selling to trend and then trend to you and you get to eat all of the customer service, it's not as if you're getting them for $16 from China (I find what is probably the same stone on alibaba), but rather you have to rely on someone who is going to deliver something that customers will accept.
There's no much difference between any of these stones. the narrative with trend and now titman stuff, and I apologize if you find it harsh, but it is my objective opinion - attempts to make the stones seem like they're differentiated from lower cost stones and attempts to create some difference in describing them vs. ezelap and DMT, which would've been important at one point. DMT and Ezelap don't have quality problems - they have a problem that three or four people can't get in line and get them to a buyer and then still have room for a retailer with returns. so they are bounced out in the return and coupon era.
I agree that laser flatness isn't practical in stones. razor users found stones delivered by the person you're mentioning either not meeting that expectation by spec or perhaps examples that didn't meet spec. But my comment also still stands, it's extremely unlikely that .0005" is a spec met over the length of the hones and to state a number that is for a fraction of the length of the stone is again, poor taste. But that's not on you, that's on the ad copy - you can't sit and write original language for everything you market.
rob's model is different than most - he had a captive market when he started (my interpretation) and could sell things to them to increase revenue when doing on-site tool classes at woodcrafts. I understand he has a large family, though perhaps most of his kids are grown now. A captive audience and an open market with full information is a different thing. After that, you can rely on reputation to sell, for example, a $16 two sided hone for $140, but it is a tax on beginners of sorts. We've all been there.
The business model has changed in general, not so much for woodworking retailers, but that there's not much risk for buyers to do something like buy the "DMD" or whatever other hone may be out there. I've been through a bunch of them and see them as consumable when there's a need to use them (steels not cut well by anything else, usually, or refurbishing something that is really high hardness). At this point, that distribution model (someone buys 500 off of alibaba, looks them over quickly and puts them on amazon for $20) is superior unless there is a great difference in product quality. The narrative is designed to imply there is.
There isn't.
And in the minority case where something comes from amazon and it may not be quite right, it can just be returned.
I took microscope pictures of a spent lower cost diamond hone last year to compare to pictures that someone else had of an old EZE-lap when they were polycrystalline or a combination of polycrystalline and monocrystalline, and all we could see is that the stones were arranged slightly more neatly. there are large diamonds initially that will come off of the stone. I would imagine that some are outside of the grading parameters (though this would be easy to work around by just making hones with diamond that's been graded for lapidary supply), but they are removed pretty quickly at the outset.
At this point, we are seeing shifting of the names on stones but they are the same thing as decades ago and in some case, not as good (the polycrystalline stones have been pretty much eliminated because monocrystalline diamonds are less expensive. there is probably still some trickle of information floating around that monocrystalline is better or implying that it's more expensive, but the new ezelap hones are not as good as the old ones).
So what am i saying? if someone is going to import a diamond hone from china (not you, the retailer, but the distributor or perhaps an industry professional who splits off), give us something new or different. it's not 30 years ago and nothing involved in the process is costly at this point. milled mild steel, electroplate and closely graded diamonds are all commodity items. The last time I checked on lapidary supply, 100 carats of 0.5 micron diamonds was about $10 direct retail. this is a fifth or a tenth of what it was 15 years ago.