I played the demo today and tried Expert to start and I just couldn't read the highway and process the button prompts fast enough. The 3 note highway looks super crowded and its hard to differentiate the white picks from the black ones. Adding the open strums and the 1 to 1 chords really ramps up the difficulty.
The gameplay is fun, and hitting the different chord combos feels good. Moving your fingers between the black and white buttons feels incredibly strange after so many years of playing plastic guitars with 5 buttons straight across! But I'm not interested in investing the time it would take to get to Expert level with this new guitar gameplay.
The FMV on-stage stuff does nothing for me. I get what they're going for, but seeing a real life generic band is somehow worse than the custom made characters in Rock Band and past Guitar Hero games.