"Extra quality" also means no one has hex-edited the file to change the region code or remove the boot logo. A pristine SCPH70012BIN will correctly identify as and will show the "Sony Computer Entertainment America" startup text.
Using the correct BIOS file is critical to making PCSX2 work. Here is how to set it up: 1. Acquiring the File (Legally) ps2 bios scph70012bin extra quality
It boots approximately 99% of the PS2 library without the glitches found in earlier "Fat" models (like the SCPH-10000). "Extra quality" also means no one has hex-edited