I have a 40GB model (CECHG) PS3, so i am out of luck at the moment i think, i can see that a lot of people with my same model have bricked. At this point i will wait for a safe solution (a 4.2x/4.3x CFW that have LV1 checks disabled) and i stay with Rogero CEX-3.55 CFW V3.7.
These last few days have been amazing for us anyway
is downgrading to 3.55 from 4.21 just as safe if you updated fine? also, everything stays in tact right? i'm just asking cause i'm pretty sure every firmware we might need to do this. maybe not though, cause it seems like everything seems to getting wide open.