The location of this apartment is PERFECT! It was a two-block walk to the same road as the Royal Mile, and then a 10 minute walk to the entrance of the Edinburgh Castle. There is a grocery store only 4 blocks away, and plenty of amazingly tasty restaurants and shopping within that same area (two amazing book stores right next to the grocery store were our favorite spots). I would HIGHLY recommend a day (or more if you have it) for the Royal Museum of Scotland. It is free admission and the architecture is breathtaking. I cannot say enough about the location of this place.
In case you are a family looking at this spot, the amount of space is really nice. However, I will say, there is a tour group that ends their tour near this home and sometimes the clapping can be a little loud in the downstairs room. Also, we were there during a festival (June), and so there was some music that was also audible from this home, but again, it doesn't go on super late, but it is there.