Well, there are several comments in their sections of different stones about how they are for razors. they've been in business for a while, and I've personally had very good experience with them (I have bought more woodworking stuff than razor stuff). They probably know enough now to know which stones are going to be good razor stones, and in reality, the criteria isn't that difficult for a good razor stone. For a superb razor stone, things are a lot tighter and there's a lot more subjectivity.
But for a good one, the particles need to be relatively small and dense, and the stone needs to be hard enough to give you the option of slurrying it or having it hold all of its grit tight.
If someone told me they were on a budget, I would tell them to take their changes with CKTG's stone. If they were on a budget, but it wasn't as strict, I'd tell them to go to alex and ask for function over beauty, and if no budget at all, I'd tell them to go to alex and ask for the nicest to use superfine stone he has.
But I stand by my comment that I wouldn't be at all afraid to order from CKTG, because I have used ozukus that are graded as finishers for woodworking, and I've used razor ozukus and the stones from CKTG are much finer than the woodworking finishers I have. If I only have one lament, it's cutting the mine into naguras and then finding out it's really too hard and fine to work without me further scuffing or cutting across the surface of the stone as naguras.
But, anyway, at this point, probably enough people have ordered stones from CKTG for razors for them to be able to tell you what people are happy with. they can certainly identify stones that are too fine to be practical for knife use, and that are not scratchy. Any stone that meets that criteria will be a pretty easy natural stone to use.