I highly recommend Jenny's apartment for anyone looking for a place to stay in Waiheke. I especially loved the white and blue decor, which added a touch of levity and the warmth to the entire place. I also appreciated the fridge being modestly well stocked, including with fresh chicken eggs (which were delicious!). The beds and furniture were old-ish but homey and clean, and added a dose of charm and character to our stay.
Location-wise, the apartment is extremely convenient, being a 3 minute drive from the Kennedy Point ferry terminal and a 5 - 10 minute drive to most other attractions, including the many wineries and restaurants the island has to offer. The apartment itself is located on a quiet residential street overlooking a lake, which makes for a great short walk.
If you're looking for a quiet, relaxing place for 2 - 3 people in Waiheke, away from the slightly more touristy areas (but not too far from the interesting stuff), give Starfish on the Bay a chance!