I definitely recommend PlaiSysUpdater too: It does MD5 hash checks, patches NATIVE_FIRM last so you can ensure a safe downgrade (If anything went wrong, you can enter recovery menu to update to a clean 10.7 OFW and try again), and only installs stuff if it doesn't already match the version you're trying to downgrade to.
All sysupdaters rely on a rather unstable kernel exploit, which requires a couple of reboots until it finally works (it's all rng, really!). None of them attempt to install anything to your NAND until they are sure they've got complete access to your entire system (kernel), but PlaiSysUpdater is probably one of the best that detects that.
If you're not going to use PlaiSysUpdater, the next best thing is SafeSysUpdater, which also does MD5-hash checking on your downgrade pack before installing them and writes to NATIVE_FIRM last.
All sysupdaters rely on a rather unstable kernel exploit, which requires a couple of reboots until it finally works (it's all rng, really!). None of them attempt to install anything to your NAND until they are sure they've got complete access to your entire system (kernel), but PlaiSysUpdater is probably one of the best that detects that.
If you're not going to use PlaiSysUpdater, the next best thing is SafeSysUpdater, which also does MD5-hash checking on your downgrade pack before installing them and writes to NATIVE_FIRM last.
