Openbolt, the Shadow is the competition series based of the SP01 pattern. It has a full dust cover and no firing pin block. Most of the ones sold in the US has what is referred to as the competition hammer. The hammer hooks are lower and cut at a better angle. The geometry gives a much better trigger pull in single action.
The two Pre B's I've worked over with competition hammers and CGW disconnectors have triggers that are every bit as good as a shadow. The single actions both break at a short and crisp 2# and the double action pull is 6# on one and 4# on the other. If you are looking for an inexpensive pistol capable of a great trigger the Pre B is a good one to work with.
