The shadow guns are made with competition in mind, you can never make a sp01 into a sp-01 shadow and run it in uspsa production.
Really what your paying for in a sp-01 shadow is the ability to shoot in production without a firing pin block and that's it.
The shadow 2 is a different animal were it was designed from the ground up just for competition and there are other features like the higher beaver tail/undercuts, increased length and weight, reduced muzzle raise, extended mag release. So with the shadow 2 your paying for more than just not having a firing pin block.