We stayed here for three nights and it was great. The apartment is 10-15 mins walk from Royal miles/Edinburgh castle area, 5-10 mins away from prince St./Waverley station. The bus station is right outside of the apartment but the city is so walkable so we didn't take public transportation at all. Also it has a great view with Calton Hill, the location is absolutely the amazing for a family size apartment.
The apartment itself was spacious with beautiful interior design. It had everything we need. The host wasn't in town when we visited, but his friend has taken care of everything efficiently. Communication was smooth too. Definitely recommend it.