The SP01 Shadow has a TAC rail that adds weight up front. This lessens muzzle flip for fast double/multiple taps.
The 75 Shadow has the same action work but no TAC rail. Like the SP01 Shadow, it has the larger bbl diameter (also adds some up front weight) and no firing pin interrupt.
The DA/SA for Production Class can be tuned to the shooter's preference. The reset is very short with the disconnector mod. The trigger pull can be reduced to 6-7# DA and 3-4# SA .
These mods can be made individually or by buying a ready-to-shoot model with grips, sights, action work, springs, short reset disconnector, ex ended firing pin, trigget etc. etc.
CZC sells models with the mods and often an extra magazine. Or will sell the individual parts needed for DIY.
CGW sell KITS designed for different shooting preferences, OR the individual parts for DIY.
So, you can buy the "basic model pistol" and add only the changes you want. Let's you get to know your pistol and tailor your choices. Is this t cheaper? Maybe.