We booked Ahu because of the view and it didn't disappoint. We loved just sitting with a glass of wine taking it all in, and the sounds of the bush too. It was quiet and like your own bit of heaven. You're well above the beach and and so it's a three-min drive down to Piha store, which worked for us, and there are some fabulous walks (Mercer Bay loop) within walking distance.
The bach itself has everything you need - the kitchen is well equipped and there is a TV for the evenings (possibly some instructions for international and hopelessly tech-illiterate visitors like us would be helpful). The bach is characterful and clearly well loved and a rich part of the owners' lives so don't expect pristine or perfect - that's not what a bach is about.
The only negative was that we didn't feel the bed linen was completely fresh. It may just have been in a cupboard too long, hence the stale smell.
We would definitely return - once experienced that view is too fab to let go of for ever.