I have a Torii, and a pair of Zu Essence with 16 ohm impedance. I would REALLY like to try this combo, but I'm afraid of damaging either the amp or the speakers. If I used the Torii on the 8 ohm setting with the Zu's, would it just be a matter of not having the volume or "hit" that the amp would have with 4 or 8 ohm speakers? Or would the outcome be something too awful to contemplate?

Any help?

I have the Torii 3 with Zu Essence  and absolutely love it.  I bought Decware based on a recommendation by Sean Casey with Zu and he was spot on.  My Torii has 4 and 8 ohm outputs.  The Essence is a very easy load for the Torii.  Spend some time experimenting with the bass and treble controls (all the controls for that matter) to dial in the performance to your liking.