I want a Downgrader too.
Im so Unhappy with my 2.71 PSP, and i was a fool and i hate me für the Upgrade.
But finding a Exploit is hard. And starting Eboots on 2.70/2.71 is only a Update and that means we need a encryption shit.
Maybe the Flash Player is our last hope?!?
sry im german that means my English is not so good