So far, the Suisin Inox Honyaki's are the thinnest blades I've handled to date. The Kohetsu has to be very close, I don't have a Suisin here with me, but the Kohetsu and Suisin represent the 2 overall thinnest knives on the website as of now, I'm guessing the Kikuichi has to be up there as well now. When it comes to thinness behind the edge there are many that are very thin, but not all of them are thin throughout the entire blade.
And please remember: "Thin" does not always equal "Good". There are people who like tougher edges and heavier knives. Personally I like thin edges with heavier bodies because I don't do high volumes of prep, and I don't abuse my edges. Added weight gives you added cutting power, but also increases fatigue. It's all about finding that happy medium that best suits you.
Just edited my last post, didn't realize how thin that Kikuichi was... it's one of the few knives I haven't handled yet. I've handled the Warikomi non-Swedish damascus, but not the Swedish one.
Anyhow back on topic about Voodoo steel. I have a tester that I finally sharpened up, (took a little longer than usual but Shapton Glass always gets the job done) 10 degrees on both sides, 8k edge... it's smoking sharp, so know that it takes refinement well.
If this is still the same one I had....it was pretty thin even by the time I got it. I believe Mark had said he got it the way I got it from the factory....he hadn't sharpened it by the time I got it in other words.
Now, if that's how all the knives would come....that would be killer. But, me suspects the edge was put on this one special.