Four criteria for a great piece of work:

1. It hooks you in 30 second previews
2. It completely absorbs you after you buy it: you can't stop playing it
and you look forward to the time you can hear it again
3. The sensations outlined in 2. don't show any signs of stopping
4. You feel passionately compelled to tell everyone about it.

This is it; one of those albums of a life time. The only downside is that there are going to be very few albums that match it in one's lifetime. It's going to be a bittersweet wait for Act III.

Steve