How can you mess up lol you only click 1 thing and your done lol some people...
i think maybe some people had problems and didnt know to use compatibility mode, i didnt even tried it on normal on my win7 x64 i just tried it with compatibility mode win98, ran it as admin and worked fine, also using old version of itunes (if it aint broken dont try and fix it )
I've only JB'd a "2G" before and I recall a lot of fiddling with recovery mode, breath holding, getting all the files you needed in advance, couple of reboots, etc. Not saying it was "hard" if you knew how to read instructions, just that Spirit is stupid easy by comparison.