I have stayed at countless Airbnb / hotels on dozens of Greek islands. My experience at Dimi's place on Kythnos was one of the best I've ever had. He and his siblings have done an incredible job renovating their family's property. It's extremely comfortable and has everything you need to enjoy your stay on the island (breathtaking view, private outdoor shower, comfy bed, good coffee + kitchen, etc). The location couldn't be better. There is a very small mostly-private beach located just under his property, and plenty of other great beaches nearby. It's about a 20' drive to the chora and also to the port, which I thought was perfect. You'll sleep listening to nothing other than the sound of waves. A perfect stay overall!