I'm not quite sure whatcha mean R3X. If you have firmware 1.5 you can use this thing to emulate other firmwares like 2.5 so that you can use the Location Player(i never actualy tried this thing lol) but it only works if your psp already has 1.5 firmware or 2.0 then u can downgrade to use it(if u want i downgraded just to try it out, it was neat but it aint worth downgrading if this is all ur downgrading for IMO but it is neat)

If you got 2.5 firmware on ur psp right now the only thing there is to do is wait for a real downgrader to come out for 2.5 or 2.6. It might take a little while but they'll get it eventually but I'd wait til it's been verified to work and is reversable before I'd try it out