Maybe not as good as getting a free guitar from Amazon, but I already have 3 so another one isn't much use. This is still a good deal, cos on Xbox 360 it's 1440 MS Points for the album.
Don't slaughter me just because you aren't getting a free guitar - I KNOW THAT! If you're a Metallica fan, the extra content is a great bonus, especially if you've already got enough guitars (2!?).