The non-numbered Sifu that jmwildenthal mentioned was what I was talking about above. Mine just came today. The side of the blade opposite the Sifu logo is blank, but otherwise it's just like the SE. I heard they only have a few of these, so it may be rarer than the SE, but probably less valuable to collectors.
This is the first time I've seen the Sifu in person, and everyone has said it before, but pictures don't do it justice. This is an impressive knife.