This place is awesome. It has a cozy feel and comfortable that you could sit in all day. The view is fantastic with the Castle from the window and Grassmarket at the street below.
We sat inside with the window open and the sounds of Grassmarket were lovely.
15(ish) minutes walk from the bus/tram for the airpot. Perfectly located to walk to nearby attractions and shopping that you can come back and chill for a while before going back out.