I didnt play rock band yet, but ive heard the medium on rock band is like the easy for GH.
I still like GH though, they came up with the whole concept and its got a real underground rock vibe to it, the sets, the graffiti, the jokes, everything... Rockband is more of a family game though.
I also love the The
Gibson Les Paul guitar wireless controller that came with the PS3!! Rock the 80s by far was my favourite in terms of the set list. Cant wait to get Guitar Hero: Aerosmith!