Fun game. If you are used to GH3, Rock band guitar should be easier, although the timing window (the time you have to hit the note before or after the note's in the window) is smaller, but it's overall easier. On GH3, I have troubles with Raining Blood and Through the Fire and Flames and a few other songs on expert, But In rock band, I've beaten every song except for Green Grass and High Tides on my first try all on expert. So yea, rockband's easier, but if you have a bunch of people at your house, it should be much more fun than GH3. GH3 is a much better first player game than Rockband.
2000th post btw.