If any metal album contained within this entire metal library deserves 5 stars then it is this one.  Tool is not a band that is going to appeal to all audiences, but what they do, they do brilliantly and this is perhaps their strongest showcase.  It is no wonder than many people looking to fine tune their hi-fi stereo systems for metal music use this album.  Not only is the production top notch but the musicianship and songwriting are above anything else I could think to recommend in this genre.  Some people have complained about the lyrics on this album.  I personally them to be a perfectly suited to the music and a compliment to songwriting in general.  If you take everything you hear 100% seriously then you are probably missing the point.