CRK uses a bushing system with Chicago screws. The bushing fits perfectly over the female screw, and the washers go on either side.
Spyderco has a bushing that is a female screw on both sides, and two male pivot screws go in from both sides, with washers on both sides. (That's kind of dirty...get your mind out of the gutter

)
Both do essentially the same thing, but I think that CRK's version, while being much more expensive to manufacture, has a few advantages. On the other hand, I'm quite impressed that Spyderco has managed to get a bushing system on knives around the $100 mark.
Oh, and I gotta say that the CF Caly 3 trumps both the Sage I and II.