I'm pretty sure the "full root" you're referring to is a NAND unlock, which means that apps don't have read/write access to /system, which is what prevents a BusyBox install (although you can install BusyBox while in Clockwork).
This method will not unlock the NAND, and its results will be similar to the one we already rooted folks have used. They've been very clear that they have a working NAND unlock (full root) but will most likely not release it... this is because if something goes wrong with the NAND unlock process, you have a brick. Flashing recovery (Clockwork) is much more versatile in this case, and gives almost the same benefits.