There is a terrific video over at Kotaku of someone playing Ace of Spades on Expert difficulty level. The difference with this video is that it's a very well-done split screen, so you can see both the notes on the screen as well as the fellow playing. And he's very, very good--he misses about ten notes during the song, which is a dominating performance.
Here's a link to the video:
http://www.kotaku.com/gaming/guitar-hero/cool-guitar-hero-split-screen-video-167346.php.
I may never actually finish this game, because I seriously doubt my ability to complete Cowboys From Hell on Expert. The opening riff is so damned difficult that it's almost impossible for me to get through, no matter how many times I play it, and dropping down to Hard and improving there doesn't help, because that riff is totally different on Hard.
Not that it matters, really. I'd like to finish it, but I've gotten such a ridiculous amount of enjoyment from the game that I can't complain if that one song turns out to be impossible. Besides, other people have finished it.
If you're in Europe and you can find the game now, this is how good it is--I've gotten several hundred e-mails about it at this point and not one has been negative. Only three, in total, even had minor complaints. It is impossible to convey how fun it is until you actually start playing that little plastic guitar--and become a rock god.
By the way, Eli 4.8 is sitting on the toilet singing "I Am the Champion" at the top of his lungs right now. I have no idea why.