We had no idea what Viaduct Harbor was like but once woke up and walked around a bit we were thrilled with our location. It is very clean, and walkable- great access and near the ferries, restaurants, bars, and Queen Street for shopping.
The room was a studio and clean and everything we needed for a comfortable stay. Lovely view of Sky Tower and cute balcony doors/windows that open out with a view. The building itself feels very safe with a gate entryway and beautiful rock garden.
Cons: Very loud at night (we heard car racing and engine revving multiple nights, people walking back from bars and loud traffic noises), no A/C so we had to have the doors open which was nice until it got loud during sleep