To understand its value, you need the timeline:
: A critical community patch that fixes the "Prop Pox" bug and crashes caused by hovering certain puzzle pieces over transit stations. simcity 4 1.1.641
There is a modern DLL called SC4Fix.dll that further patches the 1.1.641 .exe in memory to fix the "Query Tool Hang" and "Lot Footstep Bug." Drop it in your Plugins folder. To understand its value, you need the timeline: