I'm just about to finish the last 10 songs or so after playing it extremely much the last month.
Overall, it's a great game. The best in the series so far at least.
The song list was a bit disappointing though. I expected more genuine guitar rock music like Hendrix and Led Zeppelin. And I don't like how the game emphasizes more on speed and mashing than rhythm, melody and style.
The hardest songs in the game are the metal songs, which is a bit delusive. They should implement compulsory slides and make the songs more realistic instead.
And I really don't see the point in having so little content. Just implement more of the stereotype guitar classics and even the songs from the old games so one can play what one wants to listen to.
To sum it up, this game is definitely worth the money. But is it flawless? No, not by far. I would rate this game 7/10 and hoping the fourth game will be everything a rock guitar simulator should be.