If it weren't for the firing pin block on the CZs, it would SAFER in the DA/SA models than the decocker models, as the decocker models have only one hammer hook, not two, because one is removed on the decocker models to make room for the decocker mechanism. (Safer, but less safe than hammer fully down, if no FPB.)
But with the FIRING PIN BLOCK installed, its pretty much an academic discussion.
The CZ decocker models are intended to start from the half-cock notch; that's where the decocker leaves the hammer. But if you've got a decocker model, you know that.