These two places have fantastic food with great atmosphere and a little outside of the viaduct which is a little bit less hectic on a Friday or Saturday eve if that's when you were thinking of going.

Amano in Britomart (Italian) - close to Caretaker as you have referenced earlier
Baduzzi in Wynyard Quarter (also Italian)

As has been mentioned earlier, Soul has consistently great food which has established itself as one of the long-stayers but it has more of a bar vibe there especially as it gets later...