This is a really rare and special place to stay. You're right at the bottom of Calton Hill and actually inside the park. I walked up the hill a couple of mornings during my stay and the views across Edinburgh and the surrounding countryside are amazing. Checking in and out was super easy - Marco sends really clear instructions and is very responsive. The place was very clean and comfortable.
There were a couple of things I felt were missing based on the pictures shown in the profile. Marco was good about dropping over some coffee pods for the machine shown. I also found it a bit of a shame I couldn't have a wood fire - I realise it would be too much to provide wood for the stay (as someone who has a wood burner at home I know wood's not cheap) but I feel a small amount would have been appropriate, given it's winter and the log burner is shown in the pics. I guess that one's debatable!
Overall, I had a great stay and would highly recommend the place and Marco as host.