For the vast majority of users on firmware 10.50, downgrading to 9.00 is . The requirement for expensive hardware programming tools, combined with the risk of "bricking" the console due to Southbridge pairing on newer models, makes it a procedure reserved only for expert electronics technicians.
You must solder wires to the motherboard to read and patch the NOR and Syscon chips.
Firmware 9.00 is notable because it has a (using a USB exFAT exploit). Firmware 10.50 does not. Users on 10.50 sometimes want to go back to 9.00 to jailbreak.
