As a mid-lifecycle BIOS, it is incredibly stable and compatible with nearly 100% of the PS2 library.
This is the first generation of the Slimline series (V12 or V13).
It is important to address the elephant in the room:
If you are using an emulator like on a PC, Steam Deck, or Android device, the software cannot run games on its own. It requires a "dump" of a real PS2 BIOS to legally and technically function. The SCPH-70004 BIOS is highly sought after because: