2.00 to other firmwares?

ok not that the 1.51 or 1.52 is THAT useful but maybe if you swap the 1.50 downgrade with .51 that would work too? its not special but itd be cool to try it out also is there an update for 1.00 that is out (probably not because thats the lowest firmware) because if we could swap that with the 1.50 and operate on a 1.0 that'd be EVEN BETTER!

because i now have 2 1.5's and now im gonna get rid of one of them and give it to my bro because i can always downgrade now (for at least 3-4 months at least)

theoretically, yes, i dont see y not
however, i doubt its been tested, as the uses of this are....uhh...not so plentiful?
but it should be able to downgrade anyways from 1.5 up is my guess at least as long as u have the eboot. i wouldnt recommend trying it for lack of usefullness and possible risk

You cant downgrade to 1.0 even if you have the firmware file. You PSP is still 2.0 when you downgrade, it just "thinks" its 1.0. If you were to try and run the 1.0 update, you'll either brick the PSP, or at best, it will tell you that you already have the lastest version. Stop trying to hack the hack. Use it for what it was released for.