Kea is special. So is Nikolaos's place. It's nestled away on a hillside up a dirt road. You can see the stars clear as day from the windows and fall asleep to the cool breeze from the sea. There is no wifi or cellular connection which can be a blessing or curse depending on how you see things (it's a good thing, trust me).
Nikolaos is incredibly responsive and even recommended great hiking and beaches to make our trip magical. I would recommend a vehicle if you don't want to walk which can get tedious if you intend on going into the port or town often.