The Bird's Nest is extremely centrally located in Wellington. There are lots of bars and restaurants around including a bar on the floor below. This was not noisy as they closed by 2130 nightly.
The Cable car stop is only meters away and the trip up the cable car is well worth it. I would also recommend the Zealandia wildlife sanctuary. There is a free shuttle bus from the top of the cable car. If you want to see kiwis in their habitat I would recommend booking on the night tour of Zealandia ( booked up weeks in advance).
So a great central base in Wellington with quirky decor and all the equipment for self contained living.