I can warmly recommend Sheryl's house in Hahei. The house itself is very comfortable with superb views over the valley and is very conveniently located, just a couple of minutes from the village centre and 10 minutes to Hot Water Beach.
Can also recommend a visit to Hahei in mid-winter, when you basically have the place to yourself, plus the odd backpacker. The landscape and coastline is fantastic and it's not that cold either, in fact if you're brave like us you can even swim!