Overall, I would recommend the airbnb as it is in a great location to the royal mile. It has everything you need to recuperate after adventuring the city. The Click and Rent team were all very nice and reaponsive. I have no issues with their customer service and communication.
The WiFi that the other reviewers have mentioned was there. Connecting to it was fine but it was definitely a snails pace speed. It was only really usable early morning to late evening in my experience. I'm assuming due to the apartment complex possibly sharing bandwidth.
Lastly is the radiator situation. I'm not positive that it worked at keeping the room warm. If it wasn't for the small space heater provided and the warm blankets, the apartment would have been very cold.