This may sound silly, but you are not Bob Kramer. Hence, what works for Bob Kramer might not work for you... don't stare yourself blind at what a certain knife maker is using. If you ask 10 knife makers you're bound to end up with a whole bunch of answers. Ask Murray Carter and you'll be going home with the King stones. Some use diamonds, some use the Bester/Suehiro combo, some use Naniwa Chosera, some use a system with belts and polishing paste... well you get the point.
Regarding the Sharpening Stone series. They're still comparable to the super stones. Which are completely different stones than the Chosera stones (which are now called Naniwa professional).
I haven't used them personally but know not everyone who used them for knives was too happy about them, and most people consider the Chosera/Pro better stones.
One test that might be of help:
http://www.toolsfromjapan.com/wordpress/?p=672
Just keep going towards newer posts to see the other parts, there's at least 4 parts. It shows some of the weaknesses of the super-stone.
Minor problems with that test though is that it doesn't include any of the Suehiro stones, nor does it include the Ohishi stones you were looking at. Not sure if any of the Gesshin stones are in that test, but I don't think so.
But at least it might give you some idea about the Naniwa stones and what things are all about.
Personally I doubt Naniwa's really give you your money's worth in the US because they're rather overpriced there. Much of the alternatives are a lot cheaper, or at least give you a lot more stone for your money. Superstones might look cheap but you burn through them a lot faster, as you can see in those tests.