I still can not, for the life of me, pass Raining Blood on hard. I even fluked and passed One, but not Raining Blood. Only song left in entire hard campaign. Oh, and the Lou battle. Damn you Slayer and Kerry Kates!
http://www.youtube.com/watch?v=EkFaPbYKymc&feature=fvwrel
Holy cow, expert 100% Raining Blood.